Liquid discharge head, head cartridge using the liquid discharge head and liquid discharge apparatus

ABSTRACT

A liquid discharge head comprises discharge ports for discharging the liquid, a bubble producing area for producing an air bubble in the liquid of liquid flow channels, and a movable member, which is disposed toward the bubble producing area, and displaceable between a first position and a second position farther away from the bubble producing area than the first position, the liquid discharge head discharging the liquid in such a manner that the movable member is displaced from the first position to the second position by a pressure due to a bubble produced in the bubble producing area, and the bubble is more greatly expanded downstream than upstream in a direction toward the discharge port, due to the displacement of the movable member. The head has a check valve disposed in a liquid supply passage leading to the liquid flow channels.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a liquid discharge head fordischarging the desired liquid due to a bubble produced by applying heatenergy to the liquid, a head cartridge using the liquid discharge head,and a liquid discharge apparatus, and more particularly to a liquiddischarge head having a movable member which is displaceable using theproduced bubble, a head cartridge using the liquid discharge head, and aliquid discharge apparatus.

[0003] Also, this invention is applicable to a printer for recordingonto the recording medium such as paper, thread, fiber, cloths, leather,metal, plastics, glass, wood, and ceramics, a copying machine, afacsimile apparatus having a communication system, a word processorhaving a printer unit, as well as an industrial recording apparatus incombination with a variety of processors.

[0004] By the term “recording” as used in this invention is meantdepositing not only a significant image such as a character or figureonto the recording medium, but also a less significant image such as apattern thereon.

[0005] 2. Related Background Art

[0006] Conventionally, an ink jet recording method, a so-called a bubblejet recording method, has been well known wherein an image is formed onthe recording medium in such a manner as to apply the thermal energy tothe ink to bring about a state change in the ink which will cause asteep volume change (or produce a bubble) in the ink, and discharge theink from the discharge ports under the working force produced by thisstate change. A recording apparatus using this bubble jet recordingmethod has integrally arranged therein a discharge port for dischargingthe ink, an ink flow passage communicating to this discharge port, andan electricity-heat converter as energy generating means for dischargingthe ink which is disposed within an ink flow passage, as disclosed inU.S. Pat. No. 4,723,129.

[0007] With such a recording method, there are a number of advantagesthat a high-quality image can be recorded at high speed and with lownoise, and a high resolution image or a color image can be easilyrecorded by a compact apparatus, because a head for use with thisrecording method can have discharge ports for discharging the inkarranged at high density. Therefore, this bubble jet recording methodhas been recently applied to numerous office equipments such as aprinter, a copying machine, and a facsimile, as well as even anindustrial system such as a printing apparatus for cloths.

[0008] Thus, as the bubble jet technology has been utilized in variousfields of products, numerous requirements as described below have beenfurther raised in recent years.

[0009] For example, to cope with the requirements for higher energyefficiency, the optimization of a heat generating member by adjustingthe thickness of a protective membrane can be considered. This method iseffective in improving the efficiency of transferring generated heat tothe liquid.

[0010] Also, to obtain a high-quality image, a drive condition foreffecting a liquid discharge method with which the ink discharge can beexcellently made at high speed of ink discharge and based on stableproduction of bubble has been proposed, or from the viewpoint of highspeed recording, there has been proposed a liquid discharge head havingan improved shape of flow passage to attain a higher speed of refillingthe discharged liquid into liquid flow passages.

[0011] Of the shapes of flow passage, a flow passage structure as shownin FIGS. 63A and 63B, has been described in Japanese Patent ApplicationLaid-open No. 63-199972. The flow passage structure or headmanufacturing method as described in this patent paid attention to aback wave (pressure propagating in a direction opposite to the directiontoward the discharge port, i.e., pressure toward a liquid chamber 2012)which is yielded with the production of bubble. This back wave is wellknown as a loss energy as this wave does not propagate in the dischargedirection.

[0012] The invention as illustrated in FIGS. 63A and 63B discloses avalve 2010 located away from the area of producing a bubble to be formedby a heating element 2002, and opposite the discharge port 2011 withrespect to the heating element 2002.

[0013] In FIG. 63B, this valve 2010 is disclosed as having an initialposition where it is attached to a ceiling of a flow passage 2003according to a manufacturing method using a plate, and this valve ishung down in the flow passage 2003 with the production of bubble. Thisinvention is disclosed as suppressing the energy loss by controllingpart of the back wave as above mentioned with the valve 2010.

[0014] However, it will be understood that with this constitution, it isnot practical for the discharge of liquid to suppress part of the backwave with the valve 2010, by investigating when the bubble is producedwithin the flow passage 2003 holding the liquid to be discharged.

[0015] The back wave as such is not directly involved in discharging, aspreviously described. At the time when this back wave occurs within theflow passage 2003, the pressure of bubble directly involved indischarging is ready to discharge the liquid from within the flowpassage 2010, as shown in FIG. 63A. Accordingly, it is clear thatsuppressing part of the back wave has no significant effect on thedischarge.

[0016] On the other hand, in the bubble jet recording method, becausethe heating is repeated in the state where the heat generating member isin contact with the ink, there occur deposits on the surface of the heatgenerating member, due to burning of the ink, but a large amount ofdeposits might occur, depending on the type of ink, thereby resultingunstable production of bubble, which made it difficult to performexcellent ink discharge. Also, a method is desired wherein even when theliquid to be discharged is likely to degrade due to heat, or is notsufficiently bubbled, the ink can be discharged excellently withoutchanging the quality of the light to be discharged.

[0017] From such a viewpoint, a method wherein using the liquid forbubbling due to heat (bubbling liquid) and the liquid for discharging(discharge liquid) which are different, the discharge liquid isdischarged by transferring a pressure due to bubbling to the dischargeliquid has been disclosed in Japanese Patent Application Laid-open No.61-69467, Japanese Patent Application Laid-open No. 55-81172, and U.S.Pat. No. 4,480,259. In these patents, the ink which is the dischargeliquid and the bubbling liquid are completely separated via a flexiblemembrane of e.g. silicone rubber to prevent the discharge liquid frommaking direct contact with the heat generating member, and the pressuredue to bubble generation of the bubbling liquid is transferred to thedischarge liquid owing to deformation of the flexible membrane. By suchconstitution, to prevent the deposits on the surface of heat generatingmember can be attained, with a greater degree of freedom in selectingthe discharge liquid.

[0018] However, in a head in which the discharge liquid and the bubblingliquid are completely separated, as previously described, the pressuredue to bubbling will be considerably absorbed by the flexible membraneas the pressure in bubbling is transferred to the discharge liquid,owing to expansion and deformation of flexible membrane. Also, there wasa risk that the energy efficiency or discharge power may be lowered,because the deformation of flexible membrane is not very great, eventhough there is any effect in separating the discharge liquid and thebubbling liquid.

[0019] As above described, in a liquid discharge head for dischargingthe liquid due to a pressure caused by a bubble produced, it isimportant to bring about film boiling evenly. If there is any dispersionin forming the bubble, the discharge of liquid will become unstable.

[0020] Also, the liquid flow passage is divided into two portions forthe discharge liquid and the bubbling liquid, a bubble is produced inthe bubbling liquid by generating the heat with the heat generatingmember in the liquid flow passage for the bubbling liquid, and apressure due to the bubble produced is transferred to the liquid flowpassage for the discharge liquid owing to displacement of a movablemember provided between the liquid flow passage for discharge liquid andthe liquid flow passage for bubbling liquid, whereby there was a problemthat when there is any residual bubble present in the bubble generatingarea, it may disorder the displacing operation of the movable member.

[0021] Herein, there are some cases where the gas is dissolved in thebubbling liquid, so that the gas dissolved is precipitated outside dueto temperature elevation of the liquid in the continuous discharge tomake the bubbling unstable, but this can be resolved by deaeration ofthe liquid to some extent.

[0022] However, there is a problem that when the liquid discharge headis left away for a long term, the gas may be mixed again into the liquidremaining near the discharge ports or the liquid chamber.

[0023] Also, in the liquid discharge head using the movable member asabove described, there is a risk that the displacing operation of themovable member as such can not be obtained when driven at high rates of10 kHz or more, depending on the liquid used.

[0024] Still, there is a further problem that where the discharge liquidis weak to the heat, there occur burnt deposits on the heat generatingmember, if the discharge liquid is entered into the liquid flow passagefor bubbling liquid, thereby making it difficult to stably produce thebubble in the bubble producing area, and resulting in unstabledischarge.

[0025] A main subject of the present invention is to raise thefundamental discharge characteristics of the system of discharging theliquid fundamentally by forming a conventional bubble (especially abubble caused by film boiling) in the liquid flow passage to theconventionally unexpected level from the viewpoint not conceivedconventionally.

[0026] The inventors effortfully made acute researches to provide a newliquid droplet discharge method using the bubble which has not beenobtained conventionally by returning to the principle of discharging theliquid droplet, and a head for use therewith. Hereby, we made a firsttechnological analysis based on the operation of a movable member in theliquid flow passage such as analyzing the principle of the mechanism ofthe movable member in the flow passage, a second technological analysisbased on the liquid droplet discharge principle with the bubble, and athird technological analysis based on the bubble forming area of theheat generating member for forming the bubble.

[0027] From these analyses, we established a completely new technologyfor actively controlling the bubble in such a manner that in thepositional relation between the fulcrum of movable member and the freeend, the free end is located on the discharge port side, or downstream,and the movable member is disposed toward the heat generating member orthe bubble producing area.

[0028] Then, considering the energy that the bubble itself applies inthe amount of discharge, we came to realize that the growth component ofbubble on the downstream side is the greatest factor for enhancing thedischarge characteristics remarkably. That is, we found that if thegrowth component of bubble on the downstream side is transmitted to thedischarge direction efficiently, the discharge efficiency or dischargespeed will be increased. From this, the inventors reached a very hightechnical level, as compared with the conventional technical level oftransferring the growth component of bubble on the downstream sidetoward the free end of the movable member.

[0029] Further, we found that it is preferable to take intoconsideration the structural elements such as a movable member or aliquid flow passage involving in the growth of bubble in the heatgenerating area for forming the bubble, e.g., downstream from thecentral line passing through the area center of the electricity-heatconverter in the liquid flow direction, or downstream from the bubblesuch as on the area center of the face governing the bubble generation.

[0030] On the other hand, we found that the refill rate can be greatlyincreased by considering the disposition of movable member and thestructure of liquid supply passage.

[0031] Further, we found that the head having a movable member usingthat technology can take a structure of two liquid flow passagesconsisting of a first liquid flow passage communicating to the dischargeport and a second liquid flow passage containing the bubble producingarea because the gas producing area is separated from the discharge portarea, whereby there are provided a two-liquid type head using twoliquids of the discharge liquid and the bubbling liquid (different fromthe discharge liquid) and a one-liquid type head using a common liquidfor the discharge liquid and the bubbling liquid (which is practicallythe discharge liquid but different from the discharge liquid in the headof two-liquid type).

[0032] And especially in the head of two-liquid type as above described,a discharge liquid of high viscosity may be used, or the flow resistanceof the liquid flow passage on the bubble generation side may beincreased. Also, we found that in such a case, with a recovery method,as performed in a head of conventional bubble jet method, of suckingbubbles within the head or the dirt near the orifices from the orificeplate face with a pump of suction type, it is difficult to recoversufficiently both the bubbling liquid and the discharge liquid.

SUMMARY OF THE INVENTION

[0033] The inventors and the applicant have applied a superior liquiddischarge principle, the knowledge thus obtained in the researches andthe comprehensive viewpoint, but the present inventors came to recollecta more preferable idea on the premise of this invention.

[0034] A point that the present inventors have recognized, especiallythe present invention, resides in providing a liquid discharge head anda head cartridge which can relieve a burden on the recovery system ofthe main device while preventing the mixture or diffusion of two liquidsfor use to make the discharge power more stable.

[0035] A first object of the present invention is to provide a simpleand self-recoverable liquid discharge head, and a head cartridge, whichcan relieve a load on the recovery system of the main device, whilepreventing the mixture or diffusion of two liquids to make the dischargepower more stable.

[0036] A second object of the present invention is to provide a liquiddischarge head, and a head cartridge, which can greatly reduce the heataccumulation on the liquid over the heat generating member whileincreasing the discharge efficiency and the discharge pressure, and caneffect the excellent liquid discharge by reducing the residual bubbleover the heat generating member.

[0037] A third object of the present invention is to provide a liquiddischarge head, and a head cartridge, which has a higher refillfrequency and an increased printing speed by reducing the recessionamount of meniscus with the valve function of movable member, whilesuppressing the inertial force acting in a direction opposite to theliquid supply direction owing to back wave.

[0038] A fourth object of the present invention is to provide a liquiddischarge head, and a heat cartridge, which can reduce the deposits ontothe head generating member, and use the discharge liquid in variousways, with a sufficiently high discharge efficiency or discharge power.

[0039] A fifth object of the present invention is to provide a liquiddischarge head, and a head cartridge, which can raise the degree offreedom in selecting the discharge liquid.

[0040] A sixth object of the present invention is to provide a liquiddischarge head, and a head cartridge, which can be easily manufacturedas previously described.

[0041] To accomplish the above objects, the present invention provides aliquid discharge head comprising discharge ports for discharging theliquid, a bubble producing area for producing an air bubble in theliquid of liquid flow channels, and a movable member, disposed towardthe bubble producing area, which is displaceable between a firstposition and a second position farther away from the bubble producingarea than the first position, the liquid discharge head discharging theliquid in such a manner that the movable member is displaced from thefirst position to the second position owing to a pressure caused by abubble produced in the bubble producing area, and the bubble is moregreatly expanded downstream than upstream in a direction toward thedischarge port, due to the displacement of the movable member,characterized by having a check valve disposed in a liquid supplypassage leading to the liquid flow channels.

[0042] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, liquid flow channels eachhaving a heating element for applying heat to the liquid to produce abubble in the liquid, and a supply passage for supplying the liquid ontothe heating element from the upstream side of the heating element alongthe heating element, and a movable member, provided toward the heatingelement, with a free end on the discharge port side, for displacing thefree end due to a pressure caused by the bubble produced to conduct thepressure to the discharge port side, characterized by having a checkvalve disposed in the liquid supply passage.

[0043] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a heating element forapplying heat to the liquid to produce a bubble in the liquid, a movablemember, provided toward the heating element, with a free end on thedischarge port side, for displacing the free end due to a pressurecaused by the bubble produced to conduct the pressure to the dischargeport side, and a supply passage for supplying the liquid onto theheating element from the upstream side thereof along the face of themovable member closer to the heating element, characterized by having acheck valve disposed in the liquid supply passage.

[0044] Also, the invention provides a liquid discharge head comprising afirst liquid flow channel communicating to a discharge port, a secondliquid flow channel having a bubble producing area for producing abubble in the liquid by applying heat to the liquid, and a movablemember, disposed between the first liquid flow channel and the bubbleproducing area, with a free end on the discharge port side, fordisplacing the free end toward the first liquid flow channel due to apressure caused by the bubble produced within the bubble producing areato conduct the pressure to the discharge port side of the first liquidflow channel, characterized by having a check valve disposed in a liquidsupply passage leading to either one of the first and second liquid flowchannels.

[0045] Also, the invention provides a liquid discharge head comprising afirst liquid flow channel communicating to a discharge port, a secondliquid flow channel having a bubble producing area for producing abubble in the liquid by applying heat to the liquid, and a movablemember, disposed between the first liquid flow channel and the bubbleproducing area, with a free end on the discharge port side, fordisplacing the free end toward the first liquid flow channel due to apressure caused by the bubble produced within the bubble producing areato conduct the pressure to the discharge port side of the first liquidflow channel, characterized by having a check valve disposed in a liquidsupply passage leading to the first and second liquid flow channels.

[0046] Also, the invention provides a liquid discharge head comprising:

[0047] a grooved member having as a piece a plurality of discharge portsfor discharging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tothe plurality of first liquid flow channels;

[0048] an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and

[0049] a separation wall, disposed between the grooved member and theelement substrate, for composing a part of a wall for the second liquidflow channel corresponding to the heating element, and having a movablemember which is displaceable toward the first liquid flow channel by apressure due to a bubble produced at the position opposed to the heatingelement, characterized by having

[0050] a check valve disposed in a liquid supply passage leading toeither one of the first and second liquid flow channels.

[0051] Also, the invention provides a liquid discharge head comprising:

[0052] a grooved member having as a piece a plurality of discharge portsfor discharging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tothe plurality of first liquid flow channels;

[0053] an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and

[0054] a separation wall, disposed between the grooved member and theelement substrate, for composing a part of a wall for the second liquidflow channel corresponding to the heating element, and having a movablemember which is displaceable toward the first liquid flow channel by apressure due to a bubble produced at the position opposed to the heatingelement, characterized by having

[0055] a check valve disposed in a liquid supply passage leading toeither one of the first and second liquid flow channels.

[0056] Also, the invention provides a liquid discharge headcharacterized in that the check valve provided on the liquid supplypassage to the first liquid flow channel and the check valve provided onthe liquid supply passage to the second liquid flow channel havedifferent characteristics.

[0057] Also, the invention provide a liquid discharge head characterizedin that the check valve operates with a pressure different betweenliquids on both sides of the check valve.

[0058] Also, the invention provides a liquid discharge headcharacterized by comprising offset means for offsetting the pressuredifferent on which the check valve operates.

[0059] Also, the invention provides a liquid discharge headcharacterized in that the offset means is a rib which is provided to bein contact with the check valve.

[0060] Also, the invention provides a liquid discharge headcharacterized in that the check valve is formed integrally with theseparation wall.

[0061] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a bubble producing area forproducing an air bubble in the liquid of liquid flow channels, and amovable member, disposed toward the bubble producing area, which isdisplaceable between a first position and a second position farther awayfrom the bubble producing area than the first position, the liquiddischarge head discharging the liquid in such a manner that the movablemember is displaced from the first position to the second position by apressure due to a bubble produced in the bubble producing area, and thebubble is more greatly expanded downstream than upstream in a directiontoward the discharge port, due to the displacement of the movablemember, characterized by having a valve for preventing the liquid on theside of the liquid flow channel and the liquid on the opposite side fromthe liquid flow channel from mixing within a liquid supply passage intothe liquid flow channels.

[0062] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, liquid flow channels eachhaving a heating element for applying heat to the liquid to produce abubble in the liquid, and a supply passage for supplying the liquid ontothe heating element from the upstream side of the heating element alongthe heating element, and a movable member, provided toward the heatingelement, with a free end on the discharge port side, for displacing thefree end due to a pressure caused by the bubble produced to conduct thepressure to the discharge port side, characterized by having a valve forpreventing the liquid on the side of the liquid flow channel and theliquid on the opposite side from the liquid flow channel from mixingwithin a liquid supply passage into the liquid flow channel.

[0063] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a heating element forapplying heat to the liquid to produce a bubble in the liquid, a movablemember, provided toward the heating element, with a free end on thedischarge port side, for displacing the free end due to a pressurecaused by the bubble produced to conduct the pressure to the dischargeport side, and a supply passage for supplying the liquid onto theheating element from the upstream side thereof along the face of themovable member closer to the heating element, characterized by having avalve for preventing the liquid on the side of the liquid flow channeland the liquid on the opposite side from the liquid flow channel frommixing within a liquid supply passage into the liquid flow channel.

[0064] Also, the invention provides a liquid discharge head comprising afirst liquid flow channel communicating to a discharge port, a secondliquid flow channel having a bubble producing area for producing abubble in the liquid by applying heat to the liquid, and a movablemember, disposed between the first liquid flow channel and the bubbleproducing area, with a free end on the discharge port side, fordisplacing the free end toward the first liquid flow channel due to apressure caused by the bubble produced within the bubble producing areato conduct the pressure to the discharge port side of the first liquidflow channel, characterized by having a valve for preventing the liquidon the side of the liquid flow channel and the liquid on the oppositeside from the liquid flow channel from mixing within a liquid supplypassage leading to either one of the first and second liquid flowchannels.

[0065] Also, the invention provides a liquid discharge head comprising afirst liquid flow channel communicating to a discharge port, a secondliquid flow channel having a bubble producing area for producing abubble in the liquid by applying heat to the liquid, and a movablemember, disposed between the first liquid flow channel and the bubbleproducing area, with a free end on the discharge port side, fordisplacing the free end toward the first liquid flow channel due to apressure caused by the bubble produced within the bubble producing areato conduct the pressure to the discharge port side of the first liquidflow channel, characterized by having a valve for preventing the liquidon the side of the liquid flow channel and the liquid on the oppositeside from the liquid flow channel from mixing within a liquid supplypassage leading to the first and second liquid flow channels.

[0066] Also, the invention provides a liquid discharge head comprising:

[0067] a grooved member having integrally a plurality of discharge portsfor discharging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tothe plurality of first liquid flow channels;

[0068] an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and

[0069] a separation wall, disposed between the grooved member and theelement substrate, for composing a part of a wall for the second liquidflow channel corresponding to the heating element, and having a movablemember which is displaceable toward the first liquid flow channel by apressure due to a bubble produced at the position opposed to the heatingelement, characterized by having

[0070] a valve for preventing the liquid on the side of the liquid flowchannel and the liquid on the opposite side from the liquid flow channelfrom mixing within a liquid supply passage leading to either one of thefirst and second liquid flow channels.

[0071] Also, the invention provides a liquid discharge head comprising:

[0072] a grooved member having integrally a plurality of discharge portsfor discharging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tothe plurality of first liquid flow channels;

[0073] an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and

[0074] a separation wall disposed between the grooved member and theelement substrate, for composing a part of a wall for the second liquidflow channel corresponding to the heating element, and having a movablemember which is displaceable toward the first liquid flow channel by apressure due to a bubble produced at the position opposed to the heatingelement, characterized by having

[0075] a valve for preventing the liquid on the side of the liquid flowchannel and the liquid on the opposite side from the liquid flow channelfrom mixing within a liquid supply passage leading to the first andsecond liquid flow channels.

[0076] Also, the invention provides a liquid discharge headcharacterized in that the valve provided on the liquid supply passage tothe first liquid flow channel and the valve provided on the liquidsupply passage to the second liquid flow channel have differentcharacteristics.

[0077] Also, the invention provides a liquid discharge headcharacterized in that the valve operates with a pressure differencebetween liquids on both sides of the valve.

[0078] Also, the invention provides a liquid discharge headcharacterized in that the valve opens only when the pressure of liquidon the side of the liquid flow channel is lower than that on theopposite side of the liquid flow channel.

[0079] Also, the invention provides a liquid discharge headcharacterized in that the ratio between the discharge amount of liquidinto the first liquid flow channel and that into the second liquid flowchannel is controlled by the difference in characteristics between thecheck valves.

[0080] Also, the invention provides a liquid discharge headcharacterized in that the ratio between the discharge amount of liquidpassed into the first liquid flow channel and that into the secondliquid flow channel is controlled by the difference in characteristicsbetween the valves.

[0081] Also, the invention provides a liquid discharge headcharacterized by comprising a liquid tank having a positive pressure notexceeding a pressure applied onto the valve from the liquid flowchannel, when the valve begins to open.

[0082] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a bubble producing area forproducing an air bubble in the liquid of liquid flow channels, and amovable member, disposed toward the bubble producing area, which isdisplaceable between a first position and a second position farther awayfrom the bubble producing area than the first position, the liquiddischarge head discharging the liquid in such a manner that the movablemember is displaced from the first position to the second position by apressure due to a bubble produced in the bubble producing area, and thebubble is more greatly expanded downstream than upstream in a directiontoward discharge port, due to the displacement of the movable member,characterized by having a valve, disposed in a liquid supply passageleading to the liquid flow channels, which can be opened or closed owingto the bubble produced by the heating element.

[0083] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, liquid flow channels eachhaving a heating element for applying heat to the liquid to produce abubble in the liquid, and a supply passage for supplying the liquid ontothe heating element from the upstream side of the heating element alongthe heating element, and a movable member, provided toward the heatingelement, with a free end on the discharge port side, for displacing thefree end due to a pressure caused by the bubble produced to conduct thepressure to the discharge port side, characterized by having a valve,disposed in the liquid supply passage, which can be opened or closedowing to the bubble produced by the heating element.

[0084] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a heating element forapplying heat to the liquid to produce a bubble in the liquid, a movablemember, provided toward the heating element, with a free end on thedischarge port side, for displacing the free end due to a pressurecaused by the bubble produced to conduct the pressure to the dischargeport side, and a supply passage for supplying the liquid onto theheating element from the upstream side thereof along the face of themovable member closer to the heating element, characterized by having avalve disposed in the liquid supply passage, which can be opened orclosed owing to the bubble produced by the heating element.

[0085] Also, the invention provides a liquid discharge head comprising afirst liquid flow channel communicating to a discharge port, a secondliquid flow channel having a bubble producing area for producing abubble in the liquid by applying heat to the liquid, and a movablemember, disposed between the first liquid flow channel and the bubbleproducing area, with a free end on the discharge port side, fordisplacing the free end toward the first liquid flow channel due to apressure caused by the bubble produced within the bubble producing areato conduct the pressure to the discharge port side of the first liquidflow channel, characterized by having a valve, disposed in a liquidsupply passage leading to each of the liquid flow channels, which can beopened or closed owing to the bubble produced by the heating element.

[0086] Also, the invention provides a liquid discharge head comprising:

[0087] a grooved member having integrally a plurality of discharge portsfor discharging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tothe plurality of first liquid flow channels;

[0088] an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and

[0089] a separation wall, disposed between the grooved member and theelement substrate, for composing a part of a wall for the second liquidflow channel corresponding to the heating element, and having a movablemember which is displaceable toward the first liquid flow channel by apressure due to a bubble produced at the position opposed to the heatingelement, characterized by having

[0090] a valve, disposed in a liquid supply passage into the liquid flowchannels, which can be opened or closed owing to the bubble produced bythe heating element.

[0091] Also, the invention provides a liquid discharge headcharacterized in that the valve opens only when the bubble has beendisapeard.

[0092] Also, the invention provides a liquid discharge headcharacterized in that the valve opens only when liquid is supplied intothe liquid flow channel.

[0093] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a bubble producing area forproducing an air bubble in the liquid of liquid flow channels, and amovable member, disposed toward the bubble producing area, which isdisplaceable between a first position and a second position farther awayfrom the bubble producing area than the first position, the liquiddischarge head discharging the liquid in such a manner that the movablemember is displaced from the first position to the second position by apressure due to a bubble produced in the bubble producing area, and thebubble is more greatly expanded downstream than upstream in a directiontoward discharge port, due to the displacement of the movable member,characterized by having a pressure pump disposed in a liquid supplypassage into the liquid flow channels.

[0094] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, liquid flow channels eachhaving a heating element for applying heat to the liquid to produce abubble in the liquid, and a supply passage for supplying the liquid ontothe heating element from the upstream side of the heating element alongthe heating element, and a movable member, provided toward the heatingelement, with a free end on the discharge port side, for displacing thefree end due to a pressure caused by the bubble produced to conduct thepressure to the discharge port side, characterized by having a pressurepump disposed in the liquid supply passage.

[0095] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a heating element forapplying heat to the liquid to produce a bubble in the liquid, a movablemember, provided toward the heating element, with a free end on thedischarge port side, for displacing the free end due to a pressurecaused by the bubble produced to conduct the pressure to the dischargeport side, and a supply passage for supplying the liquid onto theheating element from the upstream side thereof along the face of themovable member closer to the heating element, characterized by having apressure pump disposed in the liquid supply passage.

[0096] Also, the invention provides a liquid discharge head comprising afirst liquid flow channel communicating to a discharge port, a secondliquid flow channel having a bubble producing area for producing abubble in the liquid by applying heat to the liquid, and a movablemember, disposed between the first liquid flow channel and the bubbleproducing area, with a free end on the discharge port side, fordisplacing the free end toward the first liquid flow channel due to apressure caused by the bubble produced within the bubble producing areato conduct the pressure to the discharge port side of the first liquidflow channel, characterized by having a pressure pump disposed in aliquid supply passage into each of the liquid flow channels.

[0097] Also, the invention provides a liquid discharge head comprising:

[0098] a grooved member having integrally a plurality of discharge portsfor discharging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respect discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tothe plurality of first liquid flow channels;

[0099] an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and

[0100] a separation wall, disposed between the grooved member and theelement substrate, for composing a part of a wall for the second liquidflow channel corresponding to the heating element, and having a movablemember which is displaceable toward the first liquid flow channel by apressure due to a bubble produced at the position opposed to the heatingelement, characterized by having a pressure pump disposed in a liquidsupply passage into the liquid flow channels.

[0101] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a bubble producing area forproducing an air bubble in the liquid of liquid flow channels, and amovable member, disposed toward the bubble producing area, which isdisplaceable between a first position and a second position farther awayfrom the bubble producing area than the first position, the liquiddischarge head discharging the liquid in such a manner that the movablemember is displaced from the first position to the second position by apressure due to a bubble produced in the bubble producing area, and thebubble is more greatly expanded downstream than upstream in a directiontoward discharge port, due to the displacement of the movable member,characterized in that the recovery operation for the discharge ports isperformed by discharging the liquid from the discharge ports owing topressure.

[0102] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, liquid flow channels eachhaving a heating element for applying heat to the liquid to produce abubble in the liquid, and a supply passage for supplying the liquid ontothe heating element from the upstream side of the heating element alongthe heating element, with a free end on the discharge port side, fordisplacing the free end due to a pressure caused by the bubble producedto conduct the pressure to the discharge port side, characterized inthat the recovery operation for the discharge port is performed bydischarging the liquid from the discharge ports owing to pressure.

[0103] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a heating element forapplying heat to the liquid to produce a bubble in the liquid, a movablemember, provided toward the heating element, with a free end on thedischarge port side, for displacing the free end due to a pressurecaused by the bubble produced to conduct the pressure to the dischargeport side, and a supply passage for supplying the liquid onto theheating element from the upstream side thereof along the face of themovable member closer to the heating element, characterized in that therecovery operation for the discharge ports is performed by dischargingthe liquid from the discharge ports owing to pressure.

[0104] Also, the invention provides a liquid discharge head comprising afirst liquid flow channel communicating to a discharge port, a secondliquid flow channel having a bubble producing area for producing abubble in the liquid by applying heat to the liquid, and a movablemember, disposed between the first liquid flow channel and the bubbleproducing area, with a free end on the discharge port side, fordisplacing the free end toward the first liquid flow channel due to apressure caused by the bubble produced within the bubble producing areato conduct the pressure to the discharge port side of the first liquidflow channel, characterized in that the recovery operation for thedischarge ports is performed by discharging the liquid from thedischarge ports owing to pressure.

[0105] Also, the invention provides a liquid discharge head comprising:

[0106] a grooved member having integrally a plurality of discharge portsfor discharging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tothe plurality of first liquid flow channels;

[0107] an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and

[0108] a separation wall, disposed between the grooved member and theelement substrate, for composing a part of a wall for the second liquidflow channel corresponding to the heating element, and having a movablemember which is displaceable toward the first liquid flow channel by apressure due to a bubble produced at the position opposed to the heatingelement, characterized in that the recovery operation for the dischargeports is performed by discharging the liquid from the discharge portsowing to pressure.

[0109] Also, the invention provides a liquid discharge headcharacterized in that after the recovery operation, the printingoperation is performed by discharging the liquid from the dischargeports.

[0110] Also, the invention provides a liquid discharge headcharacterized in that after the recovery operation, the printingoperation is performed by discharging the liquid from the dischargeports.

[0111] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a bubble producing area forproducing an air bubble in the liquid of liquid flow channels, and amovable member, disposed toward the bubble producing area, which isdisplaceable between a first position and a second position farther awayfrom the bubble producing area than the first position, the liquiddischarge head discharging the liquid in such a manner that the movablemember is displaced from the first position to the second position by apressure due to a bubble produced in the bubble producing area, and thebubble is more greatly expanded downstream than upstream in a directiontoward discharge port, due to the displacement of the movable member,characterized by having a cap attached to the liquid discharge headwhich allows the opening or closing of the discharge ports freely.

[0112] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, liquid flow channels eachhaving a heating element for applying heat to the liquid to produce abubble in the liquid, and a supply passage for supplying the liquid ontothe heating element from the upstream side of the heating element alongthe heating element, and a movable member, provided toward the heatingelement, with a free end on the discharge port side, for displacing thefree end due to a pressure caused by the bubble produced to conduct thepressure to the discharge port side, characterized by having a capattached to the liquid discharge head which allows the opening orclosing of the discharge ports freely.

[0113] Also, the invention provides a liquid discharge head comprisingdischarge ports for discharging the liquid, a heating element forapplying heat to the liquid to produce a bubble in the liquid, a movablemember, provided toward the heating element, with a free end on thedischarge port side, for displacing the free end due to a pressurecaused by the bubble produced to conduct the pressure to the dischargeport side, and a supply passage for supplying the liquid onto theheating element from the upstream side thereof along the face of themovable member closer to the heating element, characterized by having acap attached to the liquid discharge head which allows the opening orclosing of the discharge ports freely.

[0114] Also, the invention provides a liquid discharge head comprising,

[0115] a first liquid flow channel communicating to a discharge port,

[0116] a second liquid flow channel having a bubble producing area forproducing a bubble in the liquid by applying heat to the liquid, and

[0117] a movable member, disposed between the first liquid flow channeland the bubble producing area, with a free end on the discharge portside, for displacing the free end toward the first liquid flow channeldue to a pressure caused by the bubble produced within the bubbleproducing area to conduct the pressure to the discharge port side of thefirst liquid flow channel, characterized by further comprising,

[0118] a cap attached to the liquid discharge head which allows theopening or closing of the discharge ports freely.

[0119] Also, the invention provides a liquid discharge head comprising,

[0120] a grooved member having as a piece a plurality of discharge portsfor discharging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tothe plurality of first liquid flow channels,

[0121] an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid, and

[0122] a separation wall, disposed between the grooved member and theelement substrate, for composing a part of a wall for the second liquidflow channel corresponding to the heating element, and having a movablemember which is displaceable toward the first liquid flow channel by apressure due to a bubble produced at the position opposed to the heatingelement, characterized by further comprising,

[0123] a cap attached to the liquid discharge head which allows theopening or closing of the discharge ports freely.

[0124] Also, the invention provides a liquid discharge headcharacterized in that the cap can open or close the discharge ports bysliding with respect to the discharge ports.

[0125] Also, the invention provides a liquid discharge headcharacterized in that the cap can open or close the discharge ports byrevolving with respect to the discharge ports.

[0126] Also, the invention provides a liquid discharge headcharacterized in that the cap can open the discharge ports by separatingaway from the discharge ports, and close the discharge ports by makingclose contact with the discharge ports.

[0127] Also, the invention provides a liquid discharge headcharacterized in that the cap comprises a liquid holding member.

[0128] Also, the invention provides a liquid discharge headcharacterized in that the cap operate by movement of a carriage when theliquid discharge head is mounted on the carriage.

[0129] Also, the invention provides a liquid discharge headcharacterized in that the cap holds the liquid discharged from thedischarge ports in the recovery operation for the discharge ports.

[0130] Also, the invention provides a liquid discharge head comprising,

[0131] discharge ports from which the discharge liquid is discharged,

[0132] first liquid flow channels for conducting the discharge liquid tothe discharge ports,

[0133] heating elements for generating heat to produce a bubble in thebubbling liquid,

[0134] second liquid flow channels for conducting the bubbling liquid tothe heating elements, and

[0135] a separation wall having a movable member disposed along theheating element for separation between the first liquid flow channel andthe second liquid flow channel,

[0136] wherein the liquid discharge head discharges the discharge liquidfrom the discharge ports owing to a bubble produced,

[0137] characterized in that the bubbling liquid contains the liquidwhich has been treated for bubble generation stabilization.

[0138] Also, the invention provides a liquid discharge headcharacterized in that the separation wall is made of metal, and thebubbling liquid is predeaerated.

[0139] Also, the invention provides a liquid discharge headcharacterized by further comprising deaerating means for deaerating thebubbling liquid.

[0140] Also, the invention provides a liquid discharge headcharacterized in that the deaerating means comprises a pump for suckingthe gas from the bubbling liquid, a gas permeable membrane forpermeating only the gas from the bubbling liquid, a gas exhauster forexhausting the gas which has passed through the gas permeable membrane,and a deaerated liquid supply port for supplying the bubbling liquidwhich has been deaerated into the second liquid flow channels.

[0141] Also, the invention provides a liquid discharge headcharacterized in that the bubbling liquid is added with a burntdeposites antisticking agent.

[0142] Also, the invention provides a liquid discharge headcharacterized in that the burnt deposites antisticking agent is amaterial having the effect of exfoliating the burnt deposites which havedeposited on the heating element.

[0143] Also, the invention provides a liquid discharge headcharacterized in that the burnt deposits antisticking agent is amaterial for enhancing the wettability and having the effect ofpreventing the burnt deposites from sticking onto the heating element.

[0144] Also, the invention provides a liquid discharge headcharacterized in that the burnt deposites antisticking agent is asurfactant.

[0145] Also, the invention provides a liquid discharge headcharacterized in that the discharge liquid and the bubbling liquid arethe same liquid.

[0146] Also, the invention provides a liquid discharge headcharacterized in that the discharge liquid and the bubbling liquid aredifferent liquids from each other.

[0147] Also, the invention provides a liquid discharge head comprising,

[0148] discharge ports from which the discharge liquid is discharged,

[0149] first liquid flow channels for conducting the discharge liquid tothe discharge ports,

[0150] heating elements for generating heat to produce a bubble in thebubbling liquid,

[0151] second liquid flow channels for conducting the bubbling liquid tothe heating elements, and

[0152] a separation wall having a movable member disposed toward theheating element for separation between the first liquid flow channel andthe second liquid flow channel,

[0153] wherein the liquid discharge head discharges the discharge liquidfrom the discharge ports in such a manner that the movable member isdisplaced from the first position to the second position by a pressuredue to a bubble produced on the heating element, thereby more greatlyexpanding the bubble downstream than upstream in a direction toward thedischarge ports,

[0154] characterized in that the bubbling liquid contains the liquidwhich has been treated for bubble generation stabilization.

[0155] Also, the invention provides a liquid discharge head,characterized in that the separation wall is made of metal, and thebubbling liquid is predeaerated.

[0156] Also, the invention provides a liquid discharge headcharacterized by further comprising deaerating means for deaerating thebubbling liquid.

[0157] Also, the invention provides a liquid discharge headcharacterized in that the deaerating means comprises,

[0158] a pump for sucking the gas from the bubbling liquid,

[0159] a gas permeable membrane for permeating only the gas from thebubbling liquid,

[0160] a gas exhauster for exhausting the gas which has passed throughthe gas permeable membrane, and

[0161] a deaerated liquid supply port for supplying the bubbling liquidwhich has been deaerated into the second liquid flow channels.

[0162] Also, the invention provides a liquid discharge headcharacterized in that the bubbling liquid is added with a burntdeposites antisticking agent.

[0163] Also, the invention provides a liquid discharge headcharacterized in that the burnt deposites antisticking agent is amaterial having the effect of exfoliating the burnt deposites which havedeposited on the heating elements.

[0164] Also, the invention provides a liquid discharge headcharacterized in that the burnt deposites antisticking agent is amaterial for enhancing the wettability and having the effect ofpreventing the burnt deposites from sticking onto the heating element.

[0165] Also, the invention provide a liquid discharge head characterizedin that the burnt deposites antisticking agent is a surfactant.

[0166] Also, the invention provides a liquid discharge headcharacterized in that the discharge liquid and the bubbling liquid arethe same liquid.

[0167] Also, the invention provides a liquid discharge headcharacterized in that the discharge liquid and the bubbling liquid aredifferent liquids from each other.

[0168] Also, the invention provides a liquid discharge headcharacterized in that the gas permeable membrane is made of ethylenefluoride.

[0169] Also, the invention provides a liquid discharge headcharacterized by further comprising a valve disposed in a liquid supplypassage into the liquid flow channel, which can be opened or closedowing to a bubble produced by the heating element.

[0170] Also, the invention provides a liquid discharge headcharacterized by further comprising pressure pump disposed in a liquidsupply passage into the liquid flow channel.

[0171] Also, the invention provides a liquid discharge headcharacterized by further comprising a cap attached on the liquiddischarge head, which allows the opening and closing of the dischargeports freely.

[0172] Also, the invention provides a liquid discharge headcharacterized by further comprising a cap attached on the liquiddischarge head, which allows the opening and closing of the dischargeports freely.

[0173] Also, the invention provides a liquid discharge headcharacterized by further comprising a valve disposed in a liquid supplypassage into the liquid flow channel, which can be opened or closedowing to a bubble produced by the heating element, a pressure pumpdisposed in a liquid supply passage into the liquid flow channel, and acap attached on the liquid discharge head, which allows the opening andclosing of the discharge ports freely.

[0174] Also, the invention provides a liquid discharge headcharacterized by further comprising a valve disposed in a liquid supplypassage into the liquid flow channel, which can be opened or closedowing to a bubble produced by the heating element, a pressure pumpdisposed in a liquid supply passage into the liquid flow channel, a capattached on the liquid discharge head, which allows the opening andclosing of the discharge ports freely, and deaerating means fordeaerating the liquid within the second liquid flow channel.

[0175] Also, the invention provides a head cartridge having the liquiddischarge head, and characterized by a liquid vessel for holding theliquid to be supplied to the liquid discharge head.

[0176] Also, the invention provides a head cartridge, characterized inthat the liquid discharge head and the liquid vessel are separable.

[0177] Also, the invention provides a head cartridge, characterized inthat the liquid vessel is refilled with the liquid.

[0178] Also, the invention provides a head cartridge, characterized inthat the liquid vessel is provided with a liquid inlet opening forrefilling the liquid.

[0179] Also, the invention provides a head cartridge characterized bycomprising the liquid discharge head and liquid vessels for holding thedischarge liquid to be supplied into the first liquid flow channel andthe bubbling liquid to be supplied into the second liquid flow channel.

[0180] Also, the invention provides a head cartridge, characterized inthat the liquid vessel for holding the bubbling liquid is one fordeaerating and bubbling liquid.

[0181] Also, the invention provides a liquid discharge apparatus forperforming the recording with a liquid discharge head mounted on acarriage, the liquid discharge head comprising,

[0182] a first liquid flow channel communicating to a discharge port,

[0183] a second liquid flow channel containing a bubble producing areaand disposed adjacent the first liquid flow channel, and

[0184] a movable member, disposed toward the bubble producing area,which is displaceable between a first position and a second positionfarther away from the bubble producing area than the first position,

[0185] wherein the liquid discharge head discharges the liquid fromdischarge ports in such a manner that the movable member is displacedfrom the first position to the second position due to a pressure causedby the bubble produced within the bubble producing area to conduct thepressure in a direction toward the discharge ports, characterized byfurther comprising,

[0186] recovery means for supplying the liquid to the first and secondliquid flow channels, independently, and exhausting the liquid from thedischarge ports, and

[0187] liquid reverse flow preventing means for preventing any reverseflow of liquid from occurring in the first and second liquid flowchannels.

[0188] Also, the invention provides a liquid discharge apparatuscharacterized in that the liquid discharge head is provided with asupply system for receiving the supply from a first liquid vessel forcontaining the first liquid and a second liquid vessel for containingthe second liquid, the recovery means is provided with liquid transportmeans for transporting the liquid to the first and second liquid flowchannels, independently, and the liquid transport means transports thefirst liquid contained within the first liquid vessel to the firstliquid flow channel, and the second liquid contained within the secondliquid vessel to the second liquid flow channels, independently.

[0189] Also, the invention provides a liquid discharge apparatuscharacterized in that the liquid transport means is a pump for suckingthe liquid from the first and second liquid vessels, and forcefullyfeeding the liquid to the first and second liquid flow channels.

[0190] Also, the invention provides a liquid discharge apparatuscharacterized in that the first and second liquid vessels and the liquiddischarge head are connected via a tube, and the pump is a tube pumpusing the tube.

[0191] Also, the invention provides a liquid discharge apparatuscharacterized in that the liquid transport means is a pump forpressurizing the first and second liquid vessels and forcefully feedingthe liquid to the first and second liquid flow channels.

[0192] Also, the invention provides a liquid discharge apparatuscharacterized in that the pump is a tube pump for feeding the air intothe first and second liquid vessels.

[0193] Also, the invention provides a liquid discharge apparatuscharacterized in that the liquid discharge head and the first and secondliquid vessels are integrally constituted.

[0194] Also, the invention provides a liquid discharge apparatuscharacterized in that the deformation of tube due to a roller of thetube pump is different between the first liquid flow channel side andthe second liquid flow channel.

[0195] Also, the invention provides a liquid discharge apparatuscharacterized in that the tube pump is also used as the liquid reverseflow preventing means.

[0196] Also, the invention provides a liquid discharge apparatuscharacterized in that the liquid discharge head, the liquid vessel forsupplying the liquid to the liquid discharge head, and the liquidtransport means are mounted on a carriage.

[0197] Also, the invention provides a liquid discharge apparatuscharacterized in that the liquid discharge head and the liquid vesselfor supplying the liquid to the liquid discharge head are mounted on thecarriage, and the liquid transport means is secured to the device mainbody.

[0198] Also, the invention provides a liquid discharge apparatuscharacterized in that the liquid transport means is a pump for suckingthe liquid from the liquid vessels, and forcefully feeding the liquid tothe liquid discharge head.

[0199] Also, the invention provides a liquid discharge apparatuscharacterized in that the liquid transport means is a pump forpressurizing the liquid vessels and forcefully feeding the liquid to theliquid discharge head.

[0200] Also, the invention provides a liquid discharge apparatuscharacterized in that the liquid discharge head and the liquid vesselsare integrally constituted.

[0201] Also, the invention provides a liquid discharge apparatuscharacterized by further comprising drive signal supply means forsupplying a drive signal for discharging the liquid from the liquiddischarge head.

[0202] Also, the invention provides a liquid discharge apparatuscharacterized by further comprising recording medium conveying means forconveying the recording medium for accepting the liquid discharged fromthe liquid discharge head.

[0203] Also, the invention provides a liquid discharge apparatuscharacterized in that the recording is performed in such a manner as todischarge the ink from the liquid discharge head and attach the ink ontothe recording sheet.

[0204] Also, the invention provides a liquid discharge apparatuscharacterized in that the recording is performed in such a manner as todischarge the ink from the liquid discharge head and attach the ink ontothe cloths.

[0205] Also, the invention provides a liquid discharge apparatuscharacterized in that the recording is performed in such a manner as todischarge the ink from the liquid discharge head and attach the ink ontothe plastics.

[0206] Also, the invention provides a liquid discharge apparatuscharacterized in that the recording is performed in such a manner as todischarge the ink from the liquid discharge head and attach the ink ontothe metal.

[0207] Also, the invention provides a liquid discharge apparatuscharacterized in that the recording is performed in such a manner as todischarge the ink from the liquid discharge head and attach the ink ontothe wood.

[0208] Also, the invention provides a liquid discharge apparatuscharacterized in that the recording is performed in such a manner as todischarge the ink from the liquid discharge head and attach the ink ontothe leather.

[0209] Also, the invention provides a liquid discharge apparatuscharacterized in that the color recording is performed in such a manneras to discharge a plurality of color recording liquids from the liquiddischarge heads and attach the plurality of color recording liquids ontothe recording medium.

[0210] Also, the invention provides a liquid discharge apparatuscharacterized in that the discharge ports are arranged over an entirewidth of the recordable area for the recording medium.

[0211] Also, the invention provides a liquid discharge apparatus havinga liquid discharge head comprising discharge ports for discharging theliquid, a bubble producing area for producing an air bubble in theliquid of liquid flow channels, and a movable member, disposed towardthe bubble producing area, which is displaceable between a firstposition and a second position farther away from the bubble producingarea than the first position, the liquid discharge head discharging theliquid in such a manner that the movable member is displaced from thefirst position to the second position by a pressure due to a bubbleproduced in the bubble producing area to conduct the bubble in adischarge direction owing to displacement of the movable member, whereinthe liquid discharge apparatus is provided, in a liquid supply passageinto the liquid discharge head, with at least one of a reverse flowpreventing valve for allowing only the liquid to be flowed in a headdirection, a deaerator for removing the gas dissolved in the liquid, aliquid pump for transporting the liquid in the head direction, an activevalve which is capable of controlling the opening and closing of valve,and a cap for accepting the liquid from the discharge ports of theliquid discharge head and openably by closably attached over thedischarge ports of the head upon the operation of the carriage whichmounts the head thereon, characterized in that the reliability of liquiddischarge is enhanced with the above constitution.

[0212] Also, the invention provides a liquid discharge apparatus havinga liquid discharge head comprising a first liquid channel communicatingto discharge ports, a second liquid flow channel having a bubbleproducing area for producing an air bubble in the liquid by applyingheat to the liquid, and a movable member, disposed between the firstliquid flow channel and the bubble producing area, with a free end onthe discharge port side, for displacing the free end to the first liquidflow channel due to a pressure caused by a bubble produced within thebubble producing area, to conduct the pressure to the discharge portside of the first liquid flow channel, wherein the liquid dischargeapparatus is provided, in each liquid supply passage into the liquiddischarge head, with at least one of a reverse flow preventing valve forallowing only the liquid to be flowed in a head direction, a deaeratorfor removing the gas dissolved in the liquid, a liquid pump fortransporting the liquid in the head direction, an active valve which iscapable of controlling the opening and closing of valve, and a cap foraccepting the liquid from the discharge ports of the liquid dischargehead and openably or closably attached over the discharge ports of thehead upon the operation of the carriage which mounts the head thereon,characterized in that the reliability of liquid discharge is enhancedwith the above constitution.

BRIEF DESCRIPTION OF THE DRAWINGS

[0213]FIGS. 1A, 1B, 1C and 1D are typical cross-sectional viewsillustrating a liquid discharge head according to the present invention.

[0214]FIG. 2 is a partially cutaway perspective view of the liquiddischarge head according to the present invention.

[0215]FIG. 3 is a typical view showing the pressure propagation from abubble in the conventional head.

[0216]FIG. 4 is a typical view showing the pressure propagation from abubble in the head according to the invention.

[0217]FIG. 5 is a typical view for explaining the flow of liquid in theliquid discharge head according to the invention.

[0218]FIG. 6 is a cross-sectional view of a liquid discharge head (twoflow passages) according to the present invention.

[0219]FIG. 7 is a partially cutaway perspective view of the liquiddischarge head according to the invention.

[0220]FIGS. 8A and 8B are views for explaining the operation of amovable member.

[0221]FIG. 9 is a partially cutaway perspective view of a liquiddischarge head according to a second embodiment of the presentinvention.

[0222]FIG. 10 is a partially cutaway perspective view of a liquiddischarge head according to a third embodiment of the present invention.

[0223]FIG. 11 is a cross-sectional view of a liquid discharge headaccording to a fourth embodiment of the present invention.

[0224]FIGS. 12A, 12B and 12C are typical cross-sectional views of theliquid discharge head according to a fifth embodiment of the presentinvention.

[0225]FIG. 13 is a view for explaining the structure of a movable memberand a first liquid flow passage.

[0226]FIGS. 14A, 14B and 14C are views for explaining the structure ofthe movable member and the liquid flow passage.

[0227]FIGS. 15A, 15B and 15C are views for explaining the other shape ofthe movable member.

[0228]FIG. 16 is a graph showing the relation between the area of heatgenerating member and the ink discharge amount.

[0229]FIGS. 17A and 17B are views showing the configurational relationbetween the movable member and the heat generating member.

[0230]FIG. 18 is a graph showing the relation between the distance fromthe edge of heat generating member at the fulcrum of movable member andthe displacement amount of movable member.

[0231]FIG. 19 is a view showing the configurational relation between themovable member and the heat generating member.

[0232]FIGS. 20A and 20B are longitudinal cross-sectional views of theliquid discharge head according to the present invention.

[0233]FIG. 21 is a typical graph showing the shape of drive pulse.

[0234]FIG. 22 is a cross-sectional view for explaining a supply passageto the liquid discharge head according to the present invention.

[0235]FIG. 23 is an exploded perspective view of the head according tothe present invention.

[0236]FIGS. 24A, 24B, 24C, 24D and 24E are process drawings forexplaining a manufacturing method of the liquid discharge head accordingto the present invention.

[0237]FIGS. 25A, 25B, 25C and 25D are process drawings for explaining amanufacturing method of the liquid discharge head according to thepresent invention.

[0238]FIGS. 26A, 26B, 26C and 26D are process drawings for explaining amanufacturing method of the liquid discharge head according to thepresent invention.

[0239]FIG. 27 is an exploded perspective view of a liquid discharge headcartridge.

[0240]FIG. 28 is a schematic constitutional view of a liquid dischargeapparatus.

[0241]FIG. 29 is a block diagram of the recording apparatus.

[0242]FIG. 30 is a view showing a liquid discharge recording system.

[0243]FIG. 31 is a typical view of a head kit.

[0244]FIGS. 32A, 32B, 32C and 32D are views illustrating theconstitution of a check valve.

[0245]FIG. 33 is an enlarged view of a slit as shown in FIG. 32C.

[0246]FIGS. 34A and 34B are block diagrams of an example in which acheck valve is provided in each of the flow passages for the bubblingliquid and the discharge liquid.

[0247]FIG. 35 is a graph showing the negative pressure balance of twoliquids in an example using a check valve.

[0248]FIGS. 36A, 36B and 36C are views showing the constitution ofanother check valve.

[0249]FIG. 37 is a block diagram of an example in which a check valve isprovided in each flow passage to a liquid chamber separation type colorhead.

[0250]FIG. 38 is a block diagram of an example in which a pressure pumpfor the pressure recovery is provided in each supply passage to theliquid discharge head of the present invention.

[0251]FIG. 39 is a view showing one example of a pump.

[0252]FIGS. 40A and 40B are views for explaining a recovery deviceprovided in the recording apparatus in a third example of the presentinvention, wherein

[0253]FIG. 40A is a perspective view and

[0254]FIG. 40B is a cross-sectional view.

[0255]FIGS. 41A and 41B are views for explaining the flow resistance ofa tube pump, wherein

[0256]FIG. 41A shows the fully closed state and

[0257]FIG. 41B shows the not fully closed state.

[0258]FIG. 42 is a diagram schematically showing the drive transmissionat a home position of the tube pump.

[0259]FIG. 43 is a diagram showing a drive system provided with a drivemotor for the tube pump on the carriage.

[0260]FIGS. 44A and 44B are views for explaining the recovery device ina fourth example of the present invention, wherein

[0261]FIG. 44A is a perspective view and

[0262]FIG. 44B is a cross-sectional view.

[0263]FIGS. 45A and 45B are views for explaining the recovery device ina fifth example of the present invention, wherein

[0264]FIG. 45A is a perspective view and

[0265]FIG. 45B is a cross-sectional view.

[0266]FIGS. 46A and 46B are views showing the liquid discharge head andthe liquid vessel which are integrally constituted, wherein

[0267]FIG. 46A shows the tube pump mounted on the carriage, and

[0268]FIG. 46B shows the tube pump secured to the main unit side of therecording apparatus.

[0269]FIGS. 47A and 47B are a view for explaining the recovery device ina sixth example of the present invention, wherein

[0270]FIG. 47A is a perspective view and

[0271]FIG. 47B is a cross-sectional view.

[0272]FIG. 48 is a view showing a variation example of the pump.

[0273]FIGS. 49A, 49B, 49C and 49D are views showing a variation exampleof the pump.

[0274]FIGS. 50A, 50B, 50C and 50D are views showing a variation exampleof the pump.

[0275]FIG. 51 is a block diagram for explaining the recovery deviceprovided on the recording apparatus in a seventh example of the presentinvention.

[0276]FIGS. 52A, 52B and 52C are typical views of the head integratedwith the cap having a waste ink reservoir.

[0277]FIGS. 53A, 53B, 53C and 53D are explanatory views showing theattaching or detaching of a slide type cap onto or from the liquiddischarge head.

[0278]FIG. 54 is a block diagram in which a valve is provided in eachsupply passage to the liquid discharge head of the present invention.

[0279]FIG. 55 is a perspective view of the liquid discharge headaccording to the present invention.

[0280]FIG. 56 is an exploded perspective view of the head according tothe present invention.

[0281]FIG. 57 is an exploded perspective view of a liquid discharge headcartridge.

[0282]FIG. 58 is a cross-sectional view showing one constitutionalexample of the liquid discharge head to which a deaeration system isapplied.

[0283]FIG. 59 is a schematic view of the liquid discharge head having apressure pump, a check valve, a valve and a cap.

[0284]FIG. 60 is a typical view of an integral head system in which thewhole system is mounted on the head.

[0285]FIG. 61 is a block diagram showing the configuration of a liquiddischarge system.

[0286]FIG. 62 is a flowchart showing the control procedure of the liquiddischarge system.

[0287]FIGS. 63A and 63B are views for explaining the structure of liquidflow passage in the conventional liquid discharge head.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0288] Before describing the examples of the present invention, theliquid discharge principle for a liquid discharge head to which theinvention is applied will be described below with reference to thedrawings.

[0289] [First Embodiment]

[0290] First, an example of enhancing the discharge power or dischargeefficiency by controlling the propagating direction of pressure owing tothe bubble or the growth direction of bubble to discharge the liquidwill be given below.

[0291]FIGS. 1A to 1D are typical cross-sectional views illustrating aliquid discharge head to which the present invention is applied, andFIG. 2 is a perspective view of the liquid discharge head, partiallybroken away, according to the invention.

[0292] The liquid discharge head in this embodiment has arranged theheating elements 2 (heating resistors having the shape of 40 μm×105 μmin this embodiment) for applying the thermal energy on the liquid as thedischarge energy generating element to discharge the liquid, on anelement substrate 1, with the liquid flow passages 10 disposedcorresponding to respective heating elements 2 on the element substrate1. A liquid flow passage 10 communicates to a discharge port 18, as wellas to a common liquid chamber 13 for supplying the liquid to a pluralityof liquid flow passages 10, the same amount of liquid as that dischargedfrom the discharge ports 18 being received from this common liquidchamber 13.

[0293] On the element substrate 1 of the liquid flow passage 10, aplate-like movable member 31 made of an elastic material such as metaland having a planar portion is provided in cantilevered form, one end ofthe movable member 31 being secured to a base board (support member) 34formed by patterning the photosensitive resin on the wall of liquid flowpassage 10 or the element substrate 1. Thereby, the movable member 31 isretained and makes up a fulcrum (fulcrum portion) 33.

[0294] The movable member 31 is spaced a distance of about 15 μm awayfrom the heating element 2 to cover the heating element 2 at a positionfacing the heating element 2, in such a manner as to have the fulcrum(fulcrum portion, fixed end) 33 upstream of the great flow passing fromthe common liquid chamber 13 via the movable member 31 to the dischargeport 18, due to a discharge operation of liquid, and a free end (freeend portion) 32 downstream from the fulcrum 33. The portion between theheating element 2 and the movable member 31 is a bubble producing area11. It is to be noted that the kind or shape and the arrangement of theheating element 2 and the movable member 31 are not limited thereto, butthey may be made in any shape and arrangement capable of controlling thegrowth of bubble or the propagation of pressure, as will be describedlater. Also, the liquid flow channel 10 as above described, is dividedinto two area, a first liquid flow passage 14 which is a portiondirectly communicating to the discharge port 18, with the movable member31 as the boundary, and a second liquid flow passage 16 having thebubble producing area 11 and a liquid supply passage 12, for theexplanation of liquid flow as will be considered later.

[0295] The liquid in the bubble producing area 11 between the movablemember 31 and the heating element 2 is subjected to heat generated bythe heating element 2 to produce a bubble 40 in the liquid owing to afilm boiling phenomenon, as described in U.S. Pat. No. 4,723,129. Apressure owing to the bubble 40 produced and the bubble 40 will actpreferentially on the movable member 31, so that the movable member 31is greatly displaced around the fulcrum 33 to open toward the dischargeport 18, as shown in FIGS. 1B and 1C or FIG. 2. The propagation ofpressure owing to the bubble produced or the growth of bubble 40 itselfoccurs toward the discharge port by the displacement of the movablemember 31 or the displaced state.

[0296] Herein, one of the discharge principles which is applied in thepresent invention will be described below.

[0297] One of the important discharge principles applied in the presentinvention is that the movable member 31 disposed to face the bubble 40is displaced from the first position in the steady state to the secondposition which is a position after the displacement, owing to a pressureof the bubble 40 or the bubble 40 itself, so that the pressure by thedevelopment of bubble 40 or the bubble 40 itself is conducted downstreamwhere the discharge port 18 is disposed by this displaced movable member31.

[0298] This principle will be described below in greater detail,compared with the conventional liquid flow passage structure.

[0299]FIG. 3 is a typical view showing the propagation of pressure fromthe bubble in the conventional head, and FIG. 4 is a typical viewshowing the propagation of pressure from the bubble in the head which isapplied in the invention. Herein, note that the propagation direction ofpressure toward the discharge port is indicated by V_(A), and thepropagation direction of pressure upstream is indicated by V_(B).

[0300] In the conventional head as shown in FIG. 3, there is noconstitution of regulating the propagation direction of pressure due tothe bubble 40 produced. Therefore, the pressure propagation direction ofbubble 40 is the direction normal to the surface of bubble, as indicatedby V₁ to V₈, and thus directed in various ways. Among them, the pressurepropagation direction the component of which includes a V_(A) directionwith the greatest influence on the liquid discharge is V₁ to V₄, thatis, directional components of pressure propagation from the substantialhalf portion of bubble closer to the discharge port, which is animportant portion directly contributing to the liquid dischargeefficiency, liquid discharge power and discharge speed. Further, V₁which is closest to the discharge direction V_(A) will most efficientlywork, while V₄ has the smallest directional component toward V_(A).

[0301] On the contrary, in the embodiment as shown in FIG. 4 which isapplicable to the present invention, the movable member 31 conducts thepressure propagation directions V₁ to V₄ of bubble which were directedin various ways in FIG. 3 to the downstream side (discharge port side)and transforms them to a pressure propagation direction of V_(A),whereby the pressure of bubble 40 will directly contribute to thedischarge efficiently. And the bubble growth direction itself is alsoconducted downstream, as with the pressure propagation directions V₁ toV₄, so that the bubble will grow more greatly downstream than upstream.In this way, the fundamental improvements in the discharge efficiency,the discharge power or the discharge speed can be attained bycontrolling the bubble growth direction itself by means of the movablemember, and thus the pressure propagation direction of bubble.

[0302] Turning back to FIG. 1A to 1D, the discharge operation of theliquid discharge head in this embodiment will be described in greaterdetail.

[0303]FIG. 1A shows a state before the energy such as electrical energyis applied on the heating element 2, or before the heating element 2generates the heat.

[0304] What is important herein is that the movable member 31 isprovided at a position facing at least the downstream part of a bubbleproduced by heating of the heating element 2. Namely, the movable member31 extends at least downstream of the area center 3 of the heatingelement 2 (downstream of the line orthogonal to the length direction ofthe flow passage passing through the area center 3 of the heatingelement) on the structure of liquid flow passage, so that the downstreampart of bubble will act on the movable member 31.

[0305]FIG. 1B shows a state where the electrical energy is applied tothe heating element 2 to cause the heating element 2 to generate theheat, and heat a part of the liquid filled within the bubble producingarea 11 by the generated heat to produce a bubble 40 owing to filmboiling.

[0306] Then, the movable member 31 is displaced from the first positionto the second position, due to a pressure by the development of thebubble, to lead the pressure propagation direction of the bubble 40toward the discharge port side. What is important herein is that atleast a portion of the movable member 31 is faced to the downstreamportion of the heating element 2 or the downstream part of the bubble40, with the free end 32 of the movable member 31 disposed downstream(on the discharge port side) and the fulcrum 33 disposed upstream (onthe common liquid chamber side), as previously described.

[0307]FIG. 1C shows a state where the bubble 40 has been further grown,wherein the movable member 31 is further displaced owing to a pressureby the development of the bubble 40. The developed bubble 40 moregreatly grows downstream than upstream, and expands beyond the firstposition (as indicated by the dotted line) of the movable member 31. Inthis way, the movable member 31 is gradually displaced with the growingbubble 40 to force the pressure propagation direction of the bubble 40or the direction along which the movement of deposites is more likely tooccur, that is, the growth direction of the bubble to the free end, moreuniformly toward the discharge port 18, which is supposed to enhance thedischarge efficiency. The movable member 31 is no obstacle in conductingthe bubble 40 or the bubble generation pressure toward the dischargeport 18, and can control the pressure propagation direction or thegrowth direction of bubble 40 according to the magnitude of pressure tobe propagated.

[0308]FIG. 1D shows a state where the bubble 40 shrinks due to adecrease in the internal pressure of bubble after film boiling, aspreviously mentioned, and disappears.

[0309] The movable member 31 which has been displaced up to the secondposition returns to the initial position (first position) as indicatedin FIG. 1A, owing to a negative pressure by the contraction of bubble 40and a restoring force of the elasticity of the movable member 31 itself.Also, when the bubble disappears, the liquid flows in, as indicated bythe flows V_(D1), V_(D2) from the upstream side (B), i.e., the commonliquid chamber 13, and a flow V_(C) from the discharge port 18 tocompensate for the contraction volume of bubble 40 in the bubbleproducing area 11, and to compensate for the volume of liquid which hasbeen discharged.

[0310] Thus, the operation of the movable member owing to thedevelopment of bubble and the discharge operation of liquid have beendescribed above, but the refill of the liquid in the liquid dischargehead to which the present invention is applied will be described belowin greater detail.

[0311] Referring now to FIGS. 1A to 1D, a liquid supply mechanism whichis applied in the present invention will be described in greater detail.

[0312] After FIG. 1C, when the bubble 40 enters a bubble disappearanceprocess via a state of the maximum volume, the liquid of the volume tomake up the bubble-disappeared volume will flow into the bubbleproducing area 11 from the discharge port 18 side of the first liquidflow passage 14, as well as from the common liquid chamber 13 of thesecond liquid flow passage 16. In the conventional liquid flow passagestructure without having the movable member 31, the amount of liquidflowing into the bubble disappearance position from the discharge portside and that flowing thereinto from the common liquid chamber depend onthe flow passage resistance and the inertia of the liquid therein, whichmay be caused by the magnitude of flow resistance in the portion closerto the discharge port side than the bubble producing area and theportion closer to the common liquid chamber.

[0313] Therefore, when the flow resistance on the side closer to thedischarge port is small, it follows that a quantity of liquid will flowfrom the discharge port side into the bubble disappearance position,resulting in a great recession of meniscus. Particularly, the smallerflow resistance near the discharge port side to enhance the dischargeefficiency, the greater recession of meniscus M, when the bubbledisappears, whereby it takes a longer refill time to impede the fastprinting.

[0314] On the contrary, in this embodiment, because of the provision ofthe movable member 31, where the volume W of bubble is W1 for the upperportion from the first position of the movable member 31 as theboundary, and W2 for the bubble producing area 11, the recession ofmeniscus will stop at the time when the movable member 31 returns to anoriginal position, in bubble disappearance, whereafter the supply ofliquid amounting to the residual volume W2 is made mainly from theliquid of flow V_(D2) in the second flow passage 16. Thereby, whileconventionally about half of the volume W of bubble was the recessionamount of meniscus, it became possible to suppress the recession amountof meniscus to as small as about half of W1.

[0315] Further, since the supply of liquid by the volume W2 can beforcefully made along the face of the movable member 31 to the heatingelement, mainly from the upstream side (V_(D2)) of the second liquidflow passage 16, by the use of pressure when the bubble disappears, thefast refill could be realized.

[0316] It is characteristic herein that when making the refill using thepressure in bubble disappearance, with the conventional head, thevibration of meniscus will be larger, resulting in the degraded imagequality, whereas in the fast refill of this embodiment, the flow of theliquid through an area of the first liquid flow passage 14 at thedischarge port 18 side and the bubble producing area 11 at the dischargeport 18 side can be suppressed, thereby making the vibration of meniscusquite small.

[0317] In this way, the liquid discharge head to which the invention isapplied allows for the improved image quality or the fast recording,when used for the stable discharge or fast repetitive discharge, or inthe field of recording, by carrying out the compulsory refill into thebubble generation area via the liquid supply passage 12 of the secondflow passage 16 and the fast refill by the recession of meniscus or thesuppression of vibration as above described.

[0318] In the constitution of the liquid discharge head to which theinvention is applied, the following effective functions are alsoprovided.

[0319] It is to suppress the propagation (back wave) of pressure to theupstream side owing to development of a bubble. Of the bubble producedon the heating element 2, the pressure due to part of the bubble on thecommon liquid chamber 13 (upstream) side was mostly a force (back wave)pushing back the liquid to the upstream side. This back wave produces apressure on the upstream side, the migration amount of liquid therewith,and an inertial force by the movement of liquid, which reduced therefill of liquid into the liquid flow passage and impeded the fastdrive.

[0320] In the liquid discharge head of the invention, the refill supplyability is further increased by suppressing such action onto theupstream side by means of the movable member 31.

[0321] A further characteristic structure and effect of this embodimentwill be described below.

[0322] The second liquid flow passage 16 in this embodiment comprises aliquid supply passage 12 having an inner wall (the surface of heatingelement being not greatly depressed) substantially flat leading to theheating element 2 and upstream of the heating element 2. In this case,the supply of liquid onto the bubble producing area 11 and the surfaceof the heating element 2 occurs along the face of the movable member 31closer to the bubble producing area 11, as indicated by V_(D2).Therefore, the sediment of liquid on the surface of heating element 2 issuppressed, the deposition of gas dissolved in the liquid or theso-called residual bubble remaining without being disappeared is easilyremoved, and there is no too high heat reserve into the liquid.Accordingly, the stabler development of bubble can be repeated at highrate. While in this embodiment, the liquid supply passage 12 has asubstantially flat inner wall, it should be noted that the liquid supplypassage may smoothly lead to the surface of the heating element 2, andhave a smooth inner wall, with the shape causing no sediment of theliquid on the heating element 2 or no great turbulent in the supply ofthe liquid.

[0323] Also, the supply of liquid into the bubble producing area 11 ismade from the side of the movable member 31 (via a slit 35), asindicated by V_(D1). However, in the cases where a large movable member31 as shown in FIG. 1 to cover the whole of the bubble producting area11 (or the face of heating element) is used to conduct the pressure forproducing the bubble to the discharge port 18 more effectively, and theflow resistance of liquid is increased in the bubble producing area 11and the area of the first liquid flow passage 14 closer to the dischargeport 18, when the movable member 31 returns to the first position, theflow of liquid toward the bubble producing area 11 from V_(D1) as abovementioned is impeded. However, in the head structure of the invention,there is a flow V_(D1) to supply the liquid to the bubble producing area11, causing the supply performance of the liquid to be significantlyincreased, the supply performance of liquid is not degraded, even if astructure of covering the bubble producing area 11 with the movablemember 31 seeking the enhanced discharge efficiency is adopted.

[0324]FIG. 5 is a typical view for explaining the flow of liquid in theliquid discharge head to which the present invention is applied.

[0325] The positional relation of a free end 32 and a fulcrum 33 of themovable member 31 is such that the free end 32 is located downstreamrelative to the fulcrum 33. With such constitution, the function oreffect of leading the pressure propagation direction or the growthdirection of bubble when the bubble disappears as previously mentioned,toward the discharge port 18, can be efficiently realized. Further, thispositional relation can accomplish not only the above function or effectfor the discharge, but also the fast refill, with reduced flowresistance of the liquid flowing through a liquid flow passage 10 insupplying the liquid. This is because when a meniscus M recessed by thedischarge returns to the discharge port 18 owing to a capillary force,or when the liquid is supplied upon bubble disappearance, the free end32 and the fulcrum 33 are placed not to resist the flows S₁, S₂ and S₃passing through the liquid flow passage 10 (including the first liquidflow passage 14 and the second liquid flow passage 16), as shown in FIG.5.

[0326] Complementarily, in FIGS. 1A to 1D of this embodiment, themovable member 31 extends to the heating element 2, such that the freeend 32 of the movable member 31 is located downstream of an area center3 of halving the heating element 2 into an upstream area and adownstream area (the line orthogonal to the length direction of theliquid flow passage passing through the area central point (center) ofthe heating element), as previously described. Thereby, the movablemember 31 can receive and conduct the pressure or bubble 40 greatlycontributing to the discharge of liquid to be produced downstream of thearea center 3 of the heating element 2, toward the discharge port 18,improving the discharge efficiency or the discharge power fundamentally.

[0327] Further, various effects can be obtained using the upstream sideof bubble 40.

[0328] Also, in this embodiment, the free end of the movable member 31experiencing a momentary mechanical displacement is considered to alsoeffectively contribute to the discharge of liquid.

[0329] The head of completely separating the bubbling liquid and thedischarge liquid according to the present invention will be describedbelow.

[0330]FIG. 6 is a cross-sectional view of the liquid discharge head (twoflow passages) according to the invention, taken along the flow pathdirection, and FIG. 7 is a partially cutaway perspective view of theliquid discharge head, as shown in FIG. 6.

[0331] A main discharge principle of liquid in this example is the sameas in the previous example, except that a multiple liquid flow passageis constructed, and the heat is applied in this example, in order todistinguish between the liquid to be bubble-generated (bubbling liquid)and the liquid to be discharged (discharge liquid).

[0332] The liquid discharge head of this constitution is such that on anelement substrate 1 with the heating elements 2 for generating the heatenergy to produce a bubble in the liquid, the second liquid flowpassages 16 for bubble generation are provided, and the first liquidflow passages 14 for discharge liquid directly communicating to thedischarge ports 18 are disposed thereon.

[0333] The upstream side of the first liquid flow passages 14 is incommunication to a first common liquid chamber 15 for supplying thedischarge liquid to a plurality of first liquid supply passages 14, andthe upstream side of the second liquid flow passages 16 is incommunication to a second common liquid chamber 17 for supplying thebubbling liquid to a plurality of second liquid flow passages 16.

[0334] Between the first and second liquid flow passages, a separationwall 30 made of a material having elasticity such as metal is disposedto separate between the first liquid flow passages 14 and the secondliquid flow passages 16. When the bubbling liquid and the dischargeliquid is not to be mixed, the ventilation of liquid between the firstliquid flow passages 14 and the second liquid flow passages 16 should beprevented by this separation wall 30 as complete as possible, but whenthere is no problem even though the bubbling liquid and the dischargeliquid are mixed to some extent, it is unnecessary to provide theseparation wall 30 with the complete separation function.

[0335] A portion of the separation wall 30 located in a projection space(hereinafter a discharge pressure producing area, area A and bubbleproducing area 11 of B in FIG. 6) upward from the face direction ofheating element 2 is cantilevered from the movable member 31, with thefree end positioned on the discharge port-18 side (downstream of theliquid flow) by a slit 35, and the fulcrum 33 on the common liquidchamber side (15, 17). This movable member 31, which is disposed facingthe bubble producing area 11 of B in FIG. 6 operates to open toward thedischarge port 18 and into the first liquid flow passage 14 by bubblegeneration of the bubbling liquid (as indicated by the arrow in thefigure). Also in FIG. 7, the separation wall 30 is disposed via a spaceproviding the second liquid flow passages on the element substrate 1having arranged thereon the heating resistors as the heating elementsand the wiring electrodes 5 for applying the electrical signal to theseheating resistors.

[0336] The relation in arrangement between the fulcrum 33 and the freeend 32 of the movable member 31 and the heating element 2 is the same asin the prior embodiment.

[0337] Also, while the structural relation between the liquid supplypassage 12 and the heating element 2 was described in the priorembodiment, the structural relation between the second liquid flowpassage 16 and the heating element 2 in this embodiment is not changed.

[0338] The operation of the liquid discharge head in this embodimentwill be described below.

[0339]FIGS. 8A and 8B are views for explaining the operation of themovable member.

[0340] In driving the head, the same aqueous ink was used for thedischarge liquid to be supplied to the first liquid flow passage 14 andthe bubbling liquid to be supplied to the second liquid flow passage 16.As the heat generated by the heating element 2 acts on the bubblingliquid within the bubble producing area of the second liquid flowpassage 16, a bubble 40 is produced in the bubbling liquid in the samemanner as in the prior embodiment, owing to film boiling phenomenon, asdescribed in U.S. Pat. No. 4,723,129.

[0341] In this embodiment, because the bubble generation pressure cannot be escaped from three sides, except for the upstream side of thebubble producing area 11, the pressure due to development of this bubbleis concentrated and propagated on the movable member 31 disposed in adischarge pressure generating portion, so that the movable member 31 isdisplaced toward the first liquid flow passage 14 from the state of FIG.8A to that of FIG. 8B, with the growth of the bubble 40. By theoperation of this movable member 31, the first liquid flow passage 14and the second liquid flow passage 16 are communicated to each other, sothat the pressure due to development of the bubble 40 is mainlytransferred in a direction (as indicated by A) toward the discharge portof the first liquid flow passage 14. The liquid is discharged from thedischarge ports by the propagation of this pressure and the mechanicaldisplacement of the movable member 31 as previously described.

[0342] Then, the movable member 31 returns to a position of FIG. 8A asthe bubble contracts, and the first liquid flow passage 14 is suppliedwith the discharge liquid corresponding to the amount of dischargeliquid which has been discharged from the upstream side. Also in thisembodiment, this discharge liquid is supplied in a direction to allowthe movable member to be closed as in the prior embodiment, so that therefill of the discharge liquid is not impeded by the movable member 31.

[0343] This embodiment is the same with the action or effect of the mainportion regarding the propagation of bubble generation pressure due todisplacement of the movable member 31, the growth direction of bubble,and the prevention of back wave as in the prior embodiment, but thereare provided the following additional merits by taking the two flowpassage construction of this embodiment.

[0344] That is, according to the constitution of the embodiment as abovedescribed, the discharge liquid and the bubbling liquid are madedifferent, and the discharge liquid can be discharged by the pressuregenerated by bubble generation of the bubbling liquid. Therefore,conventionally, even with a highly viscous liquid such as polyethyleneglycol, which is difficult to generate the bubble fully by applying theheat, with less sufficient discharge power, if this liquid is suppliedto the first liquid supply passage, and a liquid for excellently bubblegeneration (about 1 to 2 cp of a mixture liquid of ethanol and waterwith the ratio of 4:6), or a liquid of low boiling point as the bubblingliquid is supplied to the second liquid flow passage 16, it is possibleto discharge excellently.

[0345] Also, as the bubbling liquid, a liquid which will not produce anyburnt deposites on the surface of the heating element by being subjectedto the heat is selected, whereby the bubble generation is stabler tomake the excellent discharge.

[0346] Further, in the head structure of the invention, a highly viscousliquid can be discharged with the higher discharge efficiency and higherdischarge power to provide the effects as described in the priorembodiment.

[0347] Also, even with a liquid which is weak to heating, if this liquidis supplied into the first liquid flow passage 14 as the dischargeliquid, and a liquid which is unliable to change in quality and canexcellently generate the bubble is supplied into the second liquid flowpassage 16, it is possible to discharge with the higher dischargeefficiency and higher discharge power without thermally damaging theliquid which is weak to heating.

[0348] [Second Embodiment]

[0349]FIG. 9 is a partially cutaway perspective view illustrating aliquid discharge head according to the second embodiment of the presentinvention.

[0350] In FIG. 9, A shows a state where a movable member 31 isdisplaced, and B shows a state where the movable member 31 is in aninitial position (first position), in which B state a bubble producingarea 11 is substantially enclosed against a discharge port 18 (a flowpassage wall, though not shown herein, exists between A and B toseparate between two flow passages).

[0351] The movable member 31 in FIG. 9 has two base boards 34 on thesides, and a liquid supply passage 12 between them. Thereby, the liquidcan be supplied along the face on the heating element 2 side of themovable member 31 and from the liquid supply passage having a facesubstantially flush with or smoothly leading from the face of theheating element 2.

[0352] Herein, at the initial position (first position) of the movablemember 31, the movable member 31 is proximate to or in close contactwith a heating element downstream wall 36 disposed downstream of theheating element 2 and transversely, and a heating element side wall 37,and is substantially enclosed against the discharge port 18 side of thebubble producing area 11. Therefore, the pressure of a bubble when thebubble is generated, particularly, the pressure downstream of thebubble, can be concentrated toward the free end of the movable member31, without leakage.

[0353] When the bubble disappears, the movable member 31 returns to thefirst position, and the supply of liquid onto the heating element 2 ismade with the bubble producing area 11 substantially enclosed on thedischarge port 18 side, whereby it is possible to obtain various effectswhich have been described in the previous embodiment such as suppressingthe recession of meniscus. Also, regarding the refill, the samefunctions and effects can be obtained as in the previous embodiment.

[0354] In this embodiment, the base board 34 for supporting and securingthe movable member 31 is disposed upstream away from the heating element2, and in a smaller width than the liquid flow passage 10, as seen fromFIGS. 2 and FIG. 9, to supply the liquid into the liquid supply passage12, as previously described. The base board 34 is not limited to theabove shape, but may be of any shape as long as the refill can besmoothly made.

[0355] While the spacing between the movable member 31 and the heatingelement 2 is as large as about 15 μm in this embodiment, it should benoted that spacing may be made in the range in which the pressure due todevelopment of the bubble can be transferred to the movable member.

[0356] [Third Embodiment]

[0357]FIG. 10 is a partially cutaway perspective view of a liquiddischarge head according to a third embodiment of the present invention.

[0358]FIG. 10 shows the positional relation between a bubble producingarea in one liquid flow passage, a bubble produced therein, and amovable member 31, to present a liquid discharge method and a refillmethod of this embodiment more clearly.

[0359] In most embodiments as previously described, the pressure of abubble produced is concentrated on a free end of the movable member 31,so that the migration of the bubble is directed toward the dischargeport 18 side at the same time with the rapid movement of the movablemember 31.

[0360] On the contrary, in this embodiment, the downstream side of thebubble, which is the discharge port 18 side of bubble, directly actingon the discharge of a liquid droplet is regulated by the free end of themovable member, while affording the degree of freedom for the bubbleproduced.

[0361] Explaining about the constitution, in FIG. 10, as opposed to FIG.2 (first embodiment) as previously described, there is not provided inthis embodiment a recess portion (as indicated by the slant lineportion) as a barrier located downstream of the bubble producing areaprovided on the element substrate 1 of FIG. 2. Namely, the free end areaand the both side end areas of the movable member 31 leaves the bubbleproducing area open against the discharge port area, withoutsubstantially enclosing it, which is the constitution of thisembodiment.

[0362] In this embodiment, since the growth of a bubble is allowed atthe leading end of the downstream portion directly acting on thedischarge of a liquid droplet of bubble, its pressure component iseffectively utilized for the discharge. In addition, since at least thepressure (components of force V₂, V₃, V₄ in FIG. 3) directed upward onthis downstream side is exerted in the free end portion of the movablemember 31 to add to the growth of bubble at the leading end of thedownstream side, the discharge efficiency can be enhanced as in theabove embodiments. This embodiment is superior in the responsibility tothe drive of the heating element 2 to the previous embodiment.

[0363] Also, this embodiment, which is simple in the construction, hasthe advantages on the manufacture.

[0364] A fulcrum portion of the movable member 31 in this embodiment issecured to a base board 34 of a smaller width than the face portion ofthe movable member 31. Accordingly, the supply of liquid into the bubbleproducing area 11, when the bubble disappears, occurs through both sidesof this base board (see the arrows in the figure). This base board maytake any structure as long as it can secure the supply ability.

[0365] The refill in supplying the liquid is superior to theconventional bubble producing structure using only the heating elements,because the flow of liquid passing into the bubble producing area fromupward as the bubble disappears is controlled, owing to the presence ofthe movable member 31 in this embodiment. Of course, the recession ofmeniscus can be thereby reduced.

[0366] As a variation of this embodiment, the movable member 31 aresubstantially enclosed only at both side ends (or one end) for the freeend thereof against the bubble producing area 11, which is preferable.According to this constitution, the pressure of the movable member 31sideways can be utilized for the growth of bubble at the end portionthereof in the discharge port 18 side, as previously described, wherebythe discharge efficiency can be further increased.

[0367] [Fourth Embodiment]

[0368] An example of enhancing the discharge power of liquid due to themechanical displacement as previously described will be described belowin this embodiment.

[0369]FIG. 11 is a cross-sectional vies of a liquid discharge headaccording to a fourth embodiment of the present invention.

[0370] In FIG. 11, a movable member 31 extends such that a free end 32of the movable member 31 is located further downstream of a heatingelement 2. Thereby, the displacement rate of the movable member 31 atthe free end 32 can be increased, and the higher discharge power due tothe displacement of the movable member 31 can be further generated.

[0371] Also, the free end 32 is positioned closer to the discharge port18 side than in the previous embodiments, making it possible toconcentrate the growth of a bubble 40 in stabler directional components,so that the more excellent discharge can be performed.

[0372] Also, the movable member 31 is displaced at a displacement rateR1 in accordance with a bubble growth rate in the central portion ofpressure of the bubble 40, but the free end 32 located farther away froma fulcrum 33 than this position is displaced at a higher rate R2.Thereby, the free end 32 is caused to mechanically act on the liquid atthe higher rate to produce the liquid movement, thereby increasing thedischarge efficiency.

[0373] Also, by making the shape of the free end normal to the liquidflow, as in FIG. 10, the pressure of the bubble 40 or the mechanicalaction of the movable member 31 can be made to contribute to thedischarge more efficiently.

[0374] [Fifth Embodiment]

[0375]FIGS. 12A, 12B and 12C are typical cross-sectional viewsillustrating a liquid discharge head according to a fifth embodiment ofthe present invention.

[0376] A structure of this embodiment, different from that of theprevious embodiment, has an area directly communicating to a dischargeport 18 which is not of the shape of the flow passage in communicationto a liquid chamber, whereby the simplification of the structure can beeffected.

[0377] All the supply of liquid occurs only from a liquid supply passage12 along the face of a movable member 31 on the bubble producing areaside, the positional relation between the free end 32 or a fulcrum 33 ofthe movable member 31 and the discharge port 18, and the constitutionthat the movable member faces a heating element 2 are the same as in theprevious embodiments.

[0378] This embodiment can accomplish the previously-mentioned effectssuch as discharge efficiency and liquid supply ability, butparticularly, the compulsory refill is effected for almost all thesupply of liquid, with the recession of meniscus suppressed, using thepressure when the bubble disappears.

[0379]FIG. 12A shows a state where the liquid is bubble-generated by theheating element 2, and FIG. 12B shows a state where the bubble iscontracting, in which state the movable member 31 returns to an initialstate and the supply of liquid occurs as at S₃.

[0380]FIG. 12C shows a state where a slight recession of meniscus M whenthe movable member 31 returns to the initial position is refilled owingto a capillary force near the discharge port 18 after the bubbledisappears.

[0381] [Other Embodiments]

[0382] While the embodiments of the liquid discharge heads or the liquiddischarge methods according to the present invention have been thusdescribed in detail, another embodiment which is preferably applicableto those embodiments will be described below with reference to thedrawings. The following explanation is applicable to either of one flowpassage type and two flow passage type in some cases, but to both types,unless particularly specified.

[0383] <Ceiling Shape of Liquid Flow Passage>

[0384]FIG. 13 is a view for explaining the structure of a movable memberand a first liquid flow passage.

[0385] As illustrated in FIG. 13, a grooved member 50 having a groovefor the first liquid flow passage 13 (or liquid flow passage 10 in FIGS.1A to 1D) is provided on a separation wall 30. In this embodiment, theheight of a ceiling of the flow passage near a free end 32 of themovable member is increased, thereby allowing for a greater operationangle θ of the movable member. The operational range of this movablemember may be determined in consideration of the structure of liquidflow passage, the durability of the movable member, and the bubblegeneration force, but desirably includes the angles up to an axial angleof the discharge port.

[0386] As shown in this figure, the displacement height of the free endof the movable member is made greater than the diameter of the dischargeport, so that the discharge power can be transferred more sufficiently.Since the height of the ceiling of liquid flow passage at a fulcrum 33of the movable member 32 is below that of the ceiling of liquid flowpassage at the free end 32 of the movable member, as shown in thefigure, the leakage of pressure wave to the upstream side due todisplacement of the movable member can be more effectively prevented.

[0387] <Configurational Relation Between Second Liquid Flow Passage andMovable Member>

[0388]FIGS. 15A, 15B and 15C are views for explaining the structure ofthe movable member and the liquid flow passage, wherein FIG. 15A is aview around the separation wall 30 and the movable member 31, as lookedfrom the above, FIG. 15B is a view of a second liquid flow passage 16,with the separation wall 30 removed, as looked from the above, and FIG.15C is a view typically showing the configurational relation between themovable member 6 and the second liquid flow passage 16, each of thesecomponents being superposed. Note that the front face of the dischargeport is located on the lower side of the figure in each case.

[0389] The second liquid flow passage 16 of this embodiment has abottleneck portion 19 on the upstream side of the heating element 2 (bythe upstream side as used herein is meant one in a large stream passingfrom a second common liquid chamber via the heating element, the movablemember and the first flow passage toward the discharge port), with thestructure of chamber (bubble generation chamber) suppressing thepressure at the time of bubble generation easily leaking to the upstreamside of the second liquid flow passage 16.

[0390] As with the conventional head, a head in which the flow passagefor bubble generation is the same as the flow passage for dischargingthe liquid, and having the bottleneck portion for preventing thepressure produced in the liquid chamber by the heating element fromleaking to the common liquid chamber, was necessary to construct suchthat the cross sectional area of the bottleneck portion is not too smallin full consideration of the refill of liquid.

[0391] In this embodiment, however, since most of the liquid to bedischarged can be the discharge liquid within the first liquid flowpassage, and the bubbling liquid within the second liquid flow passage,where the heating element is provided may not be consumed too much, thefilling amount of bubbling liquid into the bubble producing area 11 ofthe second liquid flow passage may be small. Accordingly, since thespacing at the above bottleneck portion can be as narrow as several μmto several tens μm, the pressure at the time of bubble generationproduced in the second liquid flow passage can be prevented from leakingaround too much, and concentrated onto the movable member. And sincethis pressure can be utilized as the discharge power via the movablemember 31, the higher discharge efficiency and discharge power can beachieved. Note that the shape of the first liquid flow passage 16 is notlimited to the above structure, but may be of any shape as long as thepressure by development of the bubble can be effectively transferred tothe movable member.

[0392] As shown in FIG. 15C, the lateral portion of the movable member31 covers part of a wall of the second flow liquid passage, therebypreventing the movable member 31 from dropping into the second liquidflow passage. Thus, the separation between the discharge liquid and thebubbling liquid, as previously described, can be further made. Also,since the bubble can be restrained from escaping via a slit, thedischarge pressure or discharge efficiency can be further increased.

[0393] Though a part of the bubble produced in the bubble producing areaof the second liquid flow passage extends to the first liquid flowpassage 14, with the displacement of the movable member 6 to the firstliquid flow passage 14, in FIG. 13 and FIGS. 32A to 32D, a higherdischarge power can be further obtained by making the height of thesecond flow passage to allow the bubble to extend than when the bubbledoes not extend. In this way, in order to allow the bubble to extend tothe first liquid flow passage 14, it is desirable that the height of thesecond liquid flow passage 16 is lower than that of the maximum bubble,this height being preferably several μm to 30 μm. Note that this heightwas 15 μm in this embodiment.

[0394] <Movable Member and Separation Wall>

[0395]FIGS. 15A, 15B and 15C are views for explaining other shapes ofthe movable member, wherein FIG. 15A is a view showing a rectangularshape, FIG. 15B is a view showing a shape which is slender on thefulcrum side to facilitate the operation of the movable member, and FIG.15C is a view showing a shape which is wider on the fulcrum side toraise the durability of the movable member.

[0396] In FIGS. 15A to 15C, 35 is a slit provided on the separationwall, which forms the movable member 31. As the shape for easieroperation and with good durability, a shape having a width on thefulcrum side which is circularly narrowed, as shown in FIG. 14A, ispreferable, but the shape of the movable member may be arbitrary as longas it is easily operated and has good durability, without entering thesecond liquid flow passage.

[0397] While in the previous embodiments, the plate movable member 31and the separation wall 5 with this movable member were made of nickelhaving 5 μm, it should be noted that the movable member and theseparation wall may be made of materials being solvent resistant to thebubbling liquid and the discharge liquid, and having the elasticity tosatisfactorily operate as the movable member, with which a fine slit canbe formed.

[0398] Examples of the materials for the movable member may includedurable metals such as silver, nickel, gold, iron, titanium, aluminum,platinum, tantalum, stainless steel, phosphor bronze, and their alloys,or resins having nitrile group, such as acrylonitrile, butadiene,styrene, resins having amide group, such as polyamide, resins havingcarboxyl group, such as polycarbonate, resins having aldehyde group,such as polyacetal, resins having sulfone group, such as polysulfone, aresin such as liquid crystal polymer and its compound, metals havinghighly ink resistance, such as gold, tungsten, tantalum, nickel,stainless steel, titanium, their alloys, and those coated with suchmetals or alloys on the surface for the ink resistance, resins havingamide group such as polyamide, resins having aldehyde group such aspolyacetal, resins having ketone group such as polyetheretherketone,resins having imide group such as polyimide, resins having hydroxylgroup such as phenol resin, resins having ethyl group such aspolyethylene, resins having alkyl group such as polypropylene, resinshaving epoxy group such as epoxy resins, resins having amino group suchas melamine resin, resins having methylol group such as xylene resin,and their compounds, and ceramics such as silicon dioxide, and itscompounds, which are desirable.

[0399] Examples of the materials for the separation wall may includeresins having good heat resistance, solvent resistance, and moldabilityrepresented by recent engineering plastics such as polyethylene,polypropylene, polyamide, polyethylene terephthalate, melamine resin,phenol resin, epoxy resin, polybutadiene, polyurethane,polyetheretherketone, polyethersulphone, polyallylate, polyimide,polysulphone, liquid crystal polymer (LCP), and their compounds, andmetals such as silicon dioxide, silicon nitride, nickel, gold, stainlesssteel, their alloys and their compounds, and those coated with titaniumor gold on the surface, which are desirable.

[0400] Also, the thickness of separation wall may be determined, inconsideration of its material and shape, from the viewpoint of attainingthe strength of separation wall and operating as the movable member, butdesirably is in a range from about 5 μm to about 10 μm.

[0401] While the width of slit 35 for forming the movable member 31 was2 μm in this embodiment, it will be appreciated that since the bubblingliquid and the discharge liquid are different, the slit width may belarge enough to form a meniscus between liquids if it is desired toprevent the mixture of both liquids, thereby suppressing the ventilationbetween respective liquids. For example, when a liquid of about 2 cp(centipoise) as the bubbling liquid, and a liquid of 100 cp or more asthe discharge liquid are used, the mixture of liquids can be preventedwith a slit as large as about 5 μm, but desirably may be equal to orless than 3 μm.

[0402] The movable member applicable to the invention may have athickness in the order of μm (t μm), but not be intended to have athickness in the order of cm. For the movable member having a thicknessin the order of μm, it is desirable to take into consideration thedispersion in manufacture if the slit width (W μm) in the order of μm isused.

[0403] When the thickness of a member opposed to the free end and/orside end of the movable member to form a slit is equivalent to that ofthe movable member (see FIGS. 8 and 13), the slit width and thethickness are set in the following range, in consideration of thedispersion in manufacture, whereby the mixture of the bubbling liquidand the discharge liquid can be suppressed stably. This means that inthe limited conditions, as a point of view on the design, when a highlyviscous ink (5 cp, 10 cp) is used for the bubbling liquid having aviscosity of 3 cp or less, the mixture of two liquids can be suppressedfor a long term, if W/t≦1 is satisfied.

[0404] The slit for providing a “substantially enclosed state” which isapplicable to this invention may be more surely in the order of severalμm.

[0405] As above described, the bubbling liquid and the discharge liquidare separately used, the movable member may be substantially a partitionmember for them. When this movable member is moved with the creation ofbubble, it is observed that a small amount of bubbling liquid mixes intothe discharge liquid. Considering that the discharge liquid for formingthe image has typically a color material concentration of about 3% to5%, in the ink jet recording, no great density change may occur, even ifthe bubbling liquid is contained into the discharge liquid droplet in arange of 20% or less. Accordingly, such liquid mixture composed of thebubbling liquid which is 20% or less relative to the discharge liquiddroplet and the discharge liquid are contained in the liquid dischargehead according to the invention.

[0406] In this embodiment as above described, the bubbling liquid of 15%at the upper limit is mixed, even if the viscosity is changed, and inthe bubbling liquid of 5 cp or less, this mixture ratio is about 10% atthe upper limit, depending on the drive frequency.

[0407] In particular, the smaller viscosity of the discharge liquidbelow 20 cp, the lesser mixture of liquids (e.g., 5% or less).

[0408] The configurational relation between the heating element and themovable member in this head will be described below with reference tothe drawings. Note that the shape, size and number of the movablemembers and the heating elements are not limited to the followingvalues. By the optimal arrangement between the heating element and themovable member, the pressure of forming by the heating element can beeffectively utilized as the discharge pressure.

[0409]FIG. 16 is a graph showing the relation between the area ofheating element and the ink discharge amount.

[0410] In the conventional technology relying on an ink jet recordingmethod, a so-called bubble jet recording method, in which the image isformed on the recording medium in such a manner as to bring about astate change in the ink, with a rapid volume change (i.e., developmentof a bubble), by applying the thermal energy to the ink, discharge theink from the discharge ports onto the recording medium, under theworking force owing to this state change, the area of heating elementand the ink discharge amount are in the proportional relation, as shownin FIG. 16, but it can be seen that a bubble generation ineffective areaS not contributing to the ink discharge exists. From the burnt depositson the heating element, it can be seen that this bubble generationineffective area S exists around the heating element. From theseresults, it can be said that the portion having a width of about 4 μmaround the heating element is not involved in the bubble generation.

[0411] Accordingly, to effectively utilize the bubble generationpressure, it is effective to dispose the movable member such that aportion directly above a bubble generation effective area about 4 μm ormore inside from the periphery of the heating element can be coveredwith a movable area of the movable member. While in this embodiment, thebubble generation effective area was made about 4 μm or more inside fromthe periphery of the heating element, it will be appreciated that it maynot be limited thereto, depending on the kind or forming method of theheating element.

[0412]FIG. 17 is a typical view showing the positional relation betweenthe movable member and the heating element, in which a movable member301 (FIG. 17A) and a movable member 302 (FIG. 17B) which are differentin the total movable area are disposed on the heating element 2 of58×150 μm, as looked from the above.

[0413] The dimension of the movable member 301 is 53×145 μm, which issmaller than the area of the heating element 2, but is substantiallyequal to the bubble generation effective area of the heating element 2,the movable member 301 being disposed to cover the bubble generationeffective area. On the other hand, the dimension of the movable member302 is 53×220 μm, which is larger than the area of the heating element 2(the dimension from the fulcrum to the leading end of movable member islarger than the length of heating element, with the same width), thismovable member 302 being disposed to cover the bubble generationeffective area, like the movable member 301. For the above two movablemembers 301, 302, the durability and the discharge efficiency weremeasured. The measurement conditions are as follows.

[0414] Bubbling liquid: Aqueous solution of ethanol 40%

[0415] Discharge ink: Dye ink

[0416] Voltage: 20.2 V

[0417] Frequency: 3 kHz

[0418] As a result of the experiments under the above measurementconditions, regarding the durability of the movable member, the movablemember 301 of FIG. 17A was seen to have damage on the fulcrum portion ofthe movable member 301, after applying 1×10⁷ pulses. The movable member302 of FIG. 17B was seen to have no damage, after applying 3×10⁸ pulses.Also, the kinetic energy obtained from the discharge amount and thedischarge rate with respect to the input energy was confirmed to beincreased about 1.5 to 2.5 times.

[0419] From the above results, it can be found, from both aspects of thedurability and the discharge efficiency, that it is preferential toprovide the movable member to cover the top of the bubble generationeffective area, with the area of the movable member being larger thanthat of the heating element.

[0420]FIG. 18 is a graph showing the relation between the distance fromthe edge of heating element to the fulcrum of the movable member and thedisplacement amount of movable member, and FIG. 19 is a cross-sectionalview showing the configurational relation between the heating element 2and the movable member 31, as looked from the lateral side.

[0421] The heating element 2 used was 40×105 μm. The larger distance 1from the edge of heating element 2 to the fulcrum 33 of movable member31, the greater displacement amount will be produced. Accordingly, it isdesirable that the optimal displacement amount is obtained in accordancewith the required discharge amount of ink, the flow passage structure ofdischarge liquid and the shape of heating element, and the fulcrumposition of the movable member is determined.

[0422] When the fulcrum of movable member is located immediately abovethe bubble generation effective area of heating element, a bubblegeneration pressure in addition to a stress due to displacement of themovable member is directly applied to the fulcrum, resulting in reduceddurability of the movable member. According to the experiments of thepresent inventors, it could be determined that the movable member havingthe fulcrum immediately above the bubble generation effective area wasseen to have damage on the movable wall, after applying about 1×10⁶pulses, resulting in reduced durability. Accordingly, the fulcrum of themovable member is disposed not immediately above the bubble generationeffective area of the heating element, the movable member having theshape or material having less excellent durability will still have highpracticability. Note that when the fulcrum is located immediately abovethe bubble generation effective area, the movable member can beexcellently used by selecting the shape or material. With suchconstitution, the liquid discharge head having high discharge efficiencyand durability can be obtained.

[0423] <Element Substrate>

[0424] The constitution of the element substrate having arranged thereonthe heating elements for applying the heat to the liquid will bedescribed below.

[0425]FIGS. 20A and 20B are a longitudinal cross-sectional view of theliquid discharge head according to the present invention, wherein FIG.20A is a view showing the head having a protective membrane as will bedescribed later, and FIG. 20B is a view showing the head having noprotective membrane.

[0426] A grooved member 50 having the second liquid flow passage 16, theseparation wall 30, the first liquid flow passage 14 and a groove forthe first liquid flow passage provided is placed on the elementsubstrate 1.

[0427] The element substrate 1 is formed with a silicon oxide film orsilicon nitride film 106 for the purposes of insulation and heataccumulation on a substrate 7 made of e.g. silicon, and is patternedwith an electrical resistive layer 105 (0.01 to 0.2 μm thick) made ofhafnium boride (HfB₂), tantalum nitride (TaN), tantalum aluminum (TaAl)and a wiring electrode (0.2 to 1.0 μm thick) such as aluminum, as shownin FIG. 7. A voltage is applied from these two wiring electrodes 104 tothe resistive layer 105, which is heated by electrical current passingtherethrough. A 0.1 to 2.0 μm thick protective layer made of siliconoxide or silicon nitride is formed on the resistive layer between thewiring electrodes, and an anti-cavitation layer (0.1 to 0.6 μm thick)made of tantalum is formed thereon to protect the resistive layer 105from various liquids such as the ink.

[0428] In particular, since the pressure or impulse wave produced indevelopment of a bubble or debubble generation is very strong,remarkably reducing the durability of a rigid and brittle oxide film,tantalum (Ta) of metal material is used as the anti-cavitation layer.

[0429] Also, by the combination of liquid, constitution of liquid flowpassage, and resistive material, the protective layer as above mentionedmay not be needed, and an example thereof is shown in FIG. 20B. Examplesof the resistive layer not needing such protective layer may include aniridium-tantalum-aluminum alloy.

[0430] In this way, the heating element in each embodiment as previouslydescribed may include only a resistive layer (heating portion) betweenelectrodes, or a protective layer for protecting the resistive layer.

[0431] While in this embodiment, the heating element has a heatingportion composed of a resistive layer for generating the heat inaccordance with an electrical signal as the heating element, it shouldbe noted that the heating element is not limited thereto, but may be onewhich allow the bubble sufficient to discharge the discharge liquid tobe developed in the bubbling liquid. For example, the heating elementmay be composed of a photothermal converter for generating the heat byreceiving the light such as laser, or a heating portion for generatingthe heat by receiving the high frequency.

[0432] Note that the element substrate 1 as above described may beintegrally fabricated with, in addition to the electricity-heatconverters composed of the resistive layer 105 used as the heatingportion, and the wiring electrode 104 for supplying the electricalsignal to this resistive layer, the functional devices such as atransistor, diode, latch, and shift resistor, for selectively drivingthose electricity-heat converters, through a semiconductor manufacturingprocess.

[0433] By driving the heating portions of the electricity-heatconverters disposed on the element substrate 1 as previously described,a rectangular pulse as shown in FIG. 18 is applied to the resistivelayer 105 via the wiring electrodes 14 to cause the resistive layer 105between the wiring electrodes to generate the heat rapidly, to dischargethe liquid.

[0434]FIG. 21 is a typical view showing the shape of a drive pulse.

[0435] In the head of each embodiment as previously described, theheating element was driven by applying an electrical signal having avoltage of 24, a pulse width of 7 μsec, and a current of 150 mA, at 6kHz, to discharge the liquid ink from the discharge ports through thealready-described operation. However, the conditions for the drivesignal are not limited thereto, but the drive signal may be onlyrequired to generate the bubble in the bubbling liquid properly.

[0436] <Head Structure of Two Flow Passage>

[0437] A structural example of a liquid discharge head which is capableof separately introducing different liquids into the first and secondcommon liquid chambers, with the reduced number of parts and the lowercosts, will be described below.

[0438]FIG. 22 is a cross-sectional view for explaining a supply Passageof the liquid discharge head according to the present invention, whereinlike numerals are attached to the same components as in the previousembodiments, the detail explanation of which is omitted herein.

[0439] In this embodiment, the grooved member 50 is largely comprised ofan orifice plate 51 having the discharge ports 18, a plurality ofgrooves constituting a plurality of first liquid flow passages 14, and arecess portion constituting a first common liquid chamber 15 forcommonly communicating to a plurality of liquid flow passages 14 andsupplying the discharge liquid to each of the first liquid flow passages3.

[0440] By joining the separation wall 30 to the lower portion of thisgrooved member 50, the plurality of first liquid flow passages can beformed. Such grooved member 50 has a first liquid supply passage 20leading from its upper portion to the first common liquid chamber 15.Also, the grooved member 50 has a second liquid supply passage 21leading from its upper portion through the separation wall 30 to thesecond common liquid chamber 17.

[0441] The first liquid (discharge liquid) is supplied via the firstliquid supply passage 20 to the first common liquid chamber 15 to thefirst liquid flow passage 14, as indicated by the arrow C in FIG. 22,while the second liquid (bubbling liquid) is supplied via the secondliquid supply passage 21 to the second common liquid chamber to thesecond liquid flow passage 16, as indicated by the arrow D in FIG. 22.

[0442] While in this embodiment, the second liquid supply passage 21 isdisposed parallel to the first liquid supply passage 20, it will beappreciated that the second liquid supply passage may be disposed atwill, as long as it extends through the separation wall 30 disposedoutside the first common liquid chamber 15 to communicate to the secondcommon liquid chamber 17.

[0443] Also, the size (diameter) of the second liquid supply passage 21can be determined in consideration of the supply amount of the secondliquid. The second liquid supply passage 21 may not be round in shape,but rectangular.

[0444] Also, the second common liquid chamber 17 can be formed bypartitioning the grooved member 50 with the separation wall 30. Aformation method of the second common liquid chamber 17 and the secondliquid flow passage 16 may include forming a common liquid chamber frameand a second liquid passage wall with a dry film on the elementsubstrate, and laminating a union of the grooved member 50 with theseparation wall 30 secured, to the element substrate 1, as shown in anexploded perspective view of FIG. 23.

[0445] In this embodiment, the element substrate 1 having arranged aplurality of electricity-heat converters as the heating elements forgenerating the heat to produce a bubble in the bubbling liquid, owing tofilm boiling, as previously described, is placed on a support member 70made of metal such as aluminum.

[0446] This element substrate 1 has arranged thereon a plurality ofgrooves constituting the liquid flow passages 16 formed by the secondliquid passage wall, a recess portion constituting the second commonliquid chamber (common bubbling liquid chamber) 17 for communicating toa plurality of bubbling liquid flow passages and supplying the bubblingliquid to respective bubbling liquid passages, and the separation wall30 provided with the movable wall 31.

[0447] Numeral 50 refers to the grooved member. This grooved member hasgrooves constituting the discharge liquid flow passages (first flowpassages) 14 by being joined to the separation wall 30, a recess portionconstituting the first common liquid chamber (common discharge liquidchamber) for communicating to the discharge liquid flow passages andsupplying the discharge liquid to respective discharge liquid flowpassages, a first supply passage (discharge liquid supply passage) 20for supplying the discharge liquid to the first common liquid chamber,and a second supply passages (bubbling liquid supply passage) 21 forsupplying the bubbling liquid to the second common liquid chamber 17.The second supply passage 21 leads to a communicating passage whichextends through the separation wall 30 disposed outside the first commonliquid chamber 15 to communicate to the second common liquid chamber 17,wherein through this communicating passage, the bubbling liquid can besupplied to the second common liquid chamber 15, without mixing with thedischarge liquid.

[0448] Also, the configuration relation between the element substrate 1,the separation wall 30 and the grooved ceiling 50 is such that themovable members 31 are disposed corresponding to the heating elements ofthe element substrate 1, and the discharge liquid flow passages aredisposed corresponding to the movable members 31. In this embodiment, anexample of the grooved member having one second supply passage arrangedwas offered, but a multiplicity of second supply passages may beprovided in accordance with the supply amount. Further, the flow passagecross-sectional area of the discharge liquid supply passage 20 and thebubbling liquid supply passage 21 may be determined in proportion to thesupply amount. By such optimization of the flow passage cross-sectionalarea, the components for the grooved member 50 may be miniaturized.

[0449] As above described, according to this embodiment, since thesecond supply passage for supplying the second liquid to the secondliquid flow passage and the first supply passage for supplying the firstliquid to the first liquid flow passage are constituted from the groovedceiling plate as the same grooved member, the number of components canbe reduced, and the shortened process can be realized with the lowercosts.

[0450] Since the supply of the second liquid to the second common liquidchamber communicating to the second liquid flow passage is made throughthe second liquid flow passage in a direction extending through theseparation wall for separating between the first liquid and the secondliquid, the laminating process for the separation wall, the groovedmember and a heating element forming substrate can be done only once,thereby making the fabrication easier, resulting in the improvedlaminating accuracy and the excellent discharge.

[0451] Also, since the second liquid is supplied through the separationwall to the second liquid common liquid chamber, the supply of thesecond liquid to the second liquid flow passage is more surely made, sothat the discharge can be stably effected as the sufficient supplyamount can be secured.

[0452] <Discharge Liquid, Bubbling Liquid>

[0453] The liquid discharge head according to the present invention asdescribed in the previous embodiments, with the movable member placed aspreviously described, can discharge the liquid with the higher dischargepower or discharge efficiency and at faster speed than with theconventional liquid discharge head. In this embodiment, where the sameliquid is used for the bubbling liquid and the discharge liquid, variousliquids can be used if they do not degrade due to heat applied by theheating element, are less liable to produce the deposits on the heatingelement by heating, allow for the reversible state change ofvaporization and condensation by heating, and do not cause the liquidflow passage, the movable member or the separation wall to bedeteriorated.

[0454] Among such liquids, the liquid used for recording (recordingliquid) may be the ink having a composition which has been used in theconventional bubble jet apparatus.

[0455] On the other hand, when a head of two flow passage according tothis invention is used, and the discharge liquid and the bubbling liquidare different, the bubbling liquid may be the liquid having theproperties as previously described, examples of which may specificallyinclude methanol, ethanol, n-propanol, isopropanol, n-hexane, n-heptane,n-octane, toluene, xylene, methylene dichloride, trichlene, Freon TF,Freon BF, ethyl ether, dioxane, cyclohexane, methyl acetate, ethylacetate, acetone, methyl ethyl ketone, water, and their mixtures.

[0456] As the discharge liquid, various liquids can be used,irrespective of the bubble generation ability or thermal property. Also,the liquid having poor bubble generation ability which is conventionallyinappropriate for the discharge, the liquid which may decompose ordegrade by the heat, or the highly viscous liquid, may be employed.

[0457] However, desirably, the discharge liquid must not impede thedischarge or bubble generation, or the operation of movable member bythe discharge liquid itself or the reaction with the bubbling liquid.

[0458] The discharge liquid for recording may also be a highly viscousink. Other discharge liquids may be medicines which are weak thermallyand perfume.

[0459] In the liquid discharge head according to this invention, therecording was performed using, as the recording liquid which can be usedboth for the discharge liquid and the bubbling liquid, the ink havingthe following composition, but since the discharge speed of the ink wasincreased due to enhanced discharge power, the very excellent recordedimage could be obtained with improved short accuracy of liquid droplet.Dye ink viscosity 2 cp: (C.I. food black 2) dye 3 wt % diethylene glycol10 wt % thiodiglycol 5 wt % ethanol 3 wt % water 77 wt %

[0460] Also, the recording was performed by discharging, using thebubbling liquid and the discharge liquid in combination with the liquidshaving the following compositions. Consequently, not only a liquidhaving a viscosity of several tens cp which was difficult to dischargewith the conventional head but also a liquid having a very highviscosity of 150 cp could be discharged excellently, and produced therecorded matter with high image quality. Bubbling liquid 1: ethanol 40wt % water 60 wt % Bubbling liquid 2: water 100 wt % Bubbling liquid 3:isopropyl alcohol 10 wt % water 90 wt % Discharge liquid 1: carbon black5 wt % pigment ink: styrene-acrylic acid-ethyl 1 wt % acrylate copolymer(viscosity of about 15 cp) (acid value 140, weight average molecularweight 8000) monoethanolamine 0.25 wt % glycerine 69 wt % thiodiglycol 5wt % ethanol 3 wt % water 16.75 wt % Discharge liquid 2: polyethylene100 wt % glycol 200 (viscosity of 55 cp) Discharge liquid 3:polyethylene 100 wt % glycol 600 (viscosity of 150 cp)

[0461] The head of this invention is superior to the conventional headin the respects of discharging the high viscous liquid, and dischargingthe liquid weak to the heat which may damage the discharge heater, andproduced the recorded matter of high image quality. Bubbling liquid 1:ethanol 20 wt % water 80 wt % Bubbling liquid 2: water 100 wt % Bubblingliquid 3: isopropyl alcohol 20 wt % water 80 wt % Discharge liquid 1:dye (direct yellow 86 3 wt % not purified) thiodiglycol 10 wt %glycerine 10 wt % EDTA 1 wt % (ethylenediaminetetraacetic acid) water 76wt % Discharge liquid 2: colored resin grain 10 wt % (carbon black:styrene acrylic acid resin = 1:1) thiodiglycol 10 wt % glycerine 10 wt %IPA 5 wt % water 65 wt % Discharge liquid 3: Victoria Blue GF-25(manufactured by Mikoku Shikiso Inc.)

[0462] By the way, the liquid which was conventionally difficult todischarge, as those previously cited, has a low discharge rate, thus themore dispersion in the discharge directionality and the poor shotaccuracy on the recording sheet, but also yields the dispersion indischarge amount due to discharge instability, which impeded to producethe high quality image. However, in the constitution of the aboveembodiment, the development of bubble can be made fully and stably,using the bubbling liquid. Thus, this allows the shot accuracy of liquiddroplet to be improved and the ink discharge amount to be stabler,remarkably enhancing the quality of recorded image.

[0463] <Manufacture of Liquid Discharge Head>

[0464] A manufacturing process of the liquid discharge head according tothe present invention will be described below.

[0465] For the liquid discharge head as shown in FIG. 2, the base board34 for providing the movable member 31 on the element substrate 1 isformed by patterning, and the movable member 31 is bonded or welded tothis base board 34. Thereafter, a grooved member having a plurality ofgrooves for constituting the liquid flow passages 10 and a recessportion for constituting the discharge ports 18 and the common liquidchamber 13 was joined with the element substrate 1, in the state wherethe grooves are in registration with respective movable members.

[0466] A manufacturing process of the liquid discharge head of two flowpassage as shown in FIGS. 6 and 23 will be described below.

[0467]FIG. 23 is an exploded perspective view of the head according tothe present invention.

[0468] Roughly, the head is manufactured in such a manner that the wallfor the second liquid flow passages 16 is formed on the elementsubstrate 1, the separation wall 30 is attached thereon, the further thegrooved member 50 provided with the grooves constituting the firstliquid flow passages 14 is attached thereon, or after the wall for thesecond liquid flow passages 16 is formed, the grooved member 50 havingthe separation wall 30 attached is bonded on this wall.

[0469] Further, a fabrication method of the second liquid flow passagewill be described below.

[0470]FIGS. 24A to 24E are process drawings for explaining themanufacturing method of the liquid discharge head according to thepresent invention.

[0471] In this embodiment, after the electricity-heat convertingelements having the heat generating members 2 made of hafnium boride ortantalum nitride, was formed on the element substrate (silicon wafer) 1,using the same manufacturing apparatus as that used in the semiconductormanufacturing process, as shown in FIG. 24A, the surface of the elementsubstrate 1 was washed for the purpose of providing the greater adhesionwith the photosensitive resin in the next process. Further, to increasedthe adhesion, the surface of the element substrate was reformed by theultraviolet ray-ozone, and then spin coated with a liquid of silanecoupling agent (made by Nippon Yunika: A189) diluted by ethyl alcohol to1 wt %.

[0472] Then, the surface washing was conducted as shown in FIG. 24B, anda ultraviolet sensitive resin film (made by Tokyo Ohka Kogyo Co., Ltd:dry film, Audil SY-318) DF was laminated on the substrate 1 withimproved adhesion.

[0473] Then, a photomask PM was placed on a dry film DF, as shown inFIG. 24C, and the ultraviolet ray was applied onto a portion of the dryfilm DF which is left as the second flow passage wall. This exposurestep was performed using MPA-600 made by Canon Inc., with an exposureamount of about 600 mJ/cm².

[0474] Then, the dry film DF was developed with a developer (made byTokyo Ohka Kogyo Co., Ltd: BMRC-3) composed of a mixture liquid ofxylene and butyl cellosolve acetate, the unexposed portion wasdissolved, and the exposed and cured portion was formed as the wallportion of the second liquid flow passage 16, as shown in FIG. 24D.Further, the residue on the surface of the element substrate 1 wasprocessed for about 90 seconds and removed, using an oxide plasma ashingapparatus (manufactured by Alkantec: MAS-800), and subsequently,ultraviolet radiation of 100 mJ/cm² was made at 150° C. for two hours tocompletely cure the exposed portion.

[0475] With the above method, the second liquid flow passages can beformed uniformly at high precision on a plurality of heater boards(element substrates) divided from the above silicon substrate. Thesilicon substrate was cut and separated into heater boards 1, using adicing machine (manufactured by Tokyo Seimitsu: AWD-4000) with a diamondblade having a thickness of 0.05 mm. A separated heater boards 1 wassecured onto an aluminum base plate 70 (FIG. 27) by an adhesive (made byToray Industries: SE4400). Then, a printed wiring board 71 prebonded onthe aluminum base plate 70 and the heater board 1 were connected by analuminum wire (not shown) having a diameter of 0.05 mm.

[0476] Then, a union of the grooved member 50 and the separation wall 30was bonded in registration to the heater board 1 thus obtained, as shownin FIG. 24E. That is, the grooved member having the separation wall 30and the heater board 1 are registered and firmly engaged with each otherby a presser bar spring 78, an ink and bubbling liquid supply member 80was joined on the aluminum base plate 70, and the interstice betweenaluminum wires, and between the grooved member 50, the heater board 1and the ink and bubbling liquid supply member 80 were sealed withsilicon sealant (made by Toshiba Silicone: TSE399).

[0477] With the above manufacturing method, the second liquid flowpassages can be formed onto the heater of each heater board, at highprecision and without misregistration. In particular, if the groovedmember 50 and the separation wall 30 are prebonded in the prior step,the positional precision of the first liquid flow passage 14 and themovable member 31 can be raised.

[0478] And with these high precision manufacturing technologies, thedischarge stabilization can be effected and the printing quality can beenhanced. Also, since a number of devices are fabricated collectively ona wafer, they can be mass produced at the low cost.

[0479] While in this embodiment, to form the second liquid flow passage,a ultraviolet curable dry film was used, it should be noted that it maybe formed using a resin having an absorption band in the ultravioletregion, particularly, near 248 nm, which is cured after lamination todirectly remove the portion of the resin corresponding to the secondliquid flow passage by excimer laser.

[0480] Other manufacturing methods are also provided.

[0481]FIGS. 25A to 25D are process drawings for explaining themanufacturing method of the liquid discharge head according to thepresent invention.

[0482] In this embodiment, a resist 101 having a thickness of 15 μm waspatterned on an SUS substrate 100, as shown in FIG. 25A.

[0483] Then, a nickel layer 102 was grown 15 μm thick on the SUSsubstrate 100 by electrically plating the SUS substrate 100, as shown inFIG. 25B. A plating solution used contained nickel sulfamate with astress reducing agent (made by World Metal Inc.: Zero-orle), boric acid,a pit inhibitor (made by World Metal Inc.: NP-APS), and nickel chloride.A way of applying the electric field in electrodepositing includesattaching an electrode on the anode side, and the SUS substrate 100already patterned on the cathode side, with the temperature of theplating solution being 50° C., and the current density being 5 A/cm².

[0484] Then, the SUS substrate 100 which has been plated as abovedescribed was subjected to ultrasonic vibration to exfoliate a portionof the nickel layer 102 from the SUS substrate 100, so that the desiredsecond liquid flow passage was obtained, as shown in FIG. 25C.

[0485] On the other hand, the heater boards having the electricity-heatconverting elements disposed were formed on a silicon wafer, using thesame manufacturing apparatus as that for the semiconductor. This waferwas divided into respective heater boards, using a dicing machine in thesame way as in the previous embodiment. This heater board 1 was joinedto the aluminum base plate 70 having a printed board 104 bondedbeforehand, the electrical wiring being made by connecting the printedboard 71 with the aluminum wires (not shown). Then, the second liquidflow passage obtained at the previous step was registered and secured onthe heater board 1, as shown in FIG. 25D. In securing, because this willbe engaged and contacted with the ceiling plate having the separationwall attached by a presser bar spring at a later step, in the same wayas in the first embodiment, it is sufficient to be secure enough not tocause misregistration when joining the ceiling plate therewith.

[0486] In this embodiment, an ultraviolet light curable adhesive (madeby Grace Japan: Amicon UV-300) was coated in registration as abovementioned, and secured, using an ultraviolet light irradiationapparatus, with an exposure amount of 100 mJ/cm², for the duration ofabout 3 seconds.

[0487] According to the manufacturing method of this embodiment, thesecond liquid flow passage can be obtained at high precision and withoutmisregistration relative to the heat generating member, and because theflow passage wall is made of nickel, it is possible to provide thereliable head which is strong to the alkaline liquid.

[0488] Other manufacturing methods are also provided.

[0489]FIGS. 26A to 26D are a process drawing for explaining themanufacturing method of the liquid discharge head according to thepresent invention.

[0490] In this embodiment, a resist 31 was coated on both side of an SUSsubstrate 100 having a thickness of 15 μm having alignment holes ormarks 100 a, as shown in FIG. 26A. Herein, the resist uses PMERP-AR900made by Tokyo Ohka Kogyo.

[0491] Then, the element substrate 100 was exposed in accordance withthe alignment holes 100 a, using an exposure apparatus (manufactured byCanon Inc.: MPA-600), and the resist 103 corresponding to the portion ofthe second liquid flow passage was removed, as shown in FIG. 26B. Atthis time, the exposure amount was 800 mJ/cm².

[0492] Then, the SUS substrate 100 with the resist on both sidespatterned was immersed in an etching liquid (aqueous solution of ferricchloride or cupric chloride), a portion exposed from the resist 103 wasetched, and the resist was peeled, as shown in FIG. 26C.

[0493] Then, the SUS substrate 100 which has been etched was registeredand secured on the heater board 1, in the same way as in themanufacturing method of the previous embodiment, and the liquiddischarge head having the second liquid flow passage 4 was assembled, asshown in FIG. 26D.

[0494] According to the manufacturing method of this embodiment, thesecond liquid flow passage 4 can be obtained at high precision andwithout misregistration relative to the heater, and because of the flowpassage formed by the SUS, it is possible to provide the reliable liquiddischarge head which is strong to the acid or alkaline liquid.

[0495] As above described according to the manufacturing method of thisembodiment, by disposing beforehand the second liquid flow passage wallon the element substrate, the electricity-heat converter and the secondliquid flow passage can be registered at high precision. Also, since thesecond liquid flow passages can be formed simultaneously for a number ofelement substrates on the board before cutting and separating, theliquid discharge heads can be mass produced at the low cost.

[0496] Also, a liquid discharge head obtained by carrying out themanufacturing method of the liquid discharge head according to thepresent invention can efficiently receive the pressure due to a bubbleproduced by the electricity-heat converter, resulting in excellentdischarge efficiency, because the heat generating member and the secondliquid flow passage are registered at high precision.

[0497] <Liquid Discharge Head Cartridge>

[0498] A liquid discharge head cartridge mounted with a liquid dischargehead according to the embodiment of this invention will be roughlydescribed below.

[0499]FIG. 27 is an exploded perspective view of the liquid dischargehead cartridge.

[0500] As shown in FIG. 27, the liquid discharge head cartridge roughlyconsists of a liquid discharge head portion 200 and a liquid vessel 90.

[0501] The liquid discharge head portion 200 is composed of an elementsubstrate 1, a separation wall 30, a grooved member 50, a presser barspring 78, a liquid supply member 90, and a support member 70. On theelement substrate 1 are provided a plurality of heating resistors forapplying the heat to the bubbling liquid as previously described in arow, and a plurality of function elements for driving these heatingresistors selectively. A bubbling liquid passage is formed between thiselement substrate 1 and the separation wall 30 having the movable wallto allow the bubbling liquid to pass therethrough. By joining thisseparation wall 30 with the grooved ceiling plate 50, a discharge liquidpassage (not shown) is formed to allow the discharge liquid to passtherethrough.

[0502] The presser bar spring 78 is a member for urging the groovedmember 50 toward the element substrate 1, with which the elementsubstrate 1, the separation wall 30, the grooved member 50 and thesupport member 70 are integrated securely.

[0503] The support member is to support the element substrate 1, and hasarranged thereon a circuit board 71 connecting to the element substrate1 for supplying an electrical signal, and a compact pad 72 connecting tothe apparatus side for communicating an electrical signal to theapparatus side.

[0504] The liquid vessel 90 contains the discharge liquid such as theink to be supplied to the liquid discharge head and the bubbling liquidfor producing the bubble, separated by a partition. A registration part94 for registering a connection member for connecting the liquiddischarge head and the liquid vessel and rigid shafts 95 for securingthe connection portion are provided outside the liquid vessel 90. Thesupply of the discharge liquid is made from a discharge liquid supplypassage 92 through a supply passage 84 of the connecting member to adischarge liquid supply passage 81 of a liquid supply member 80, andthrough the discharge liquid supply passages 83, 71, 21 for each memberto the first common liquid chamber. The supply of the bubbling liquid isalso made from a supply passage 93 of the liquid vessel through thesupply passage of the connecting member to the bubbling liquid supplypassage 82 of the liquid supply member 80 to the bubbling liquid supplypassage 82, and through the bubbling liquid supply passages 84, 71, 22to the second liquid chamber.

[0505] While in the liquid discharge head cartridge as above described,the supply passages and the liquid vessels are provided, when thebubbling liquid and the discharge liquid are different, it will beappreciated that the supply passages and the liquid vessels for thebubbling liquid and the discharge liquid may not be separately provided.

[0506] Note that these liquid vessels may be reused by refiling theliquid, after the liquid is used up. To this end, it is desirable that aliquid inlet opening is provided in the liquid vessel. Also, the liquiddischarge head and the liquid vessel may be provided integrally orseparably.

[0507] <Liquid Discharge Apparatus>

[0508]FIG. 28 is a schematic constitutional view of a liquid dischargeapparatus.

[0509] A carriage HC of the liquid discharge apparatus which isexplained particularly using an ink discharge recording apparatus withthe ink as the discharge liquid is mounted with a head cartridge havingdetachably a liquid tank 90 for containing the ink and a liquiddischarge head portion 200, the head cartridge being reciprocated in thewidth direction of the recording medium 150 such as the recording sheetwhich is conveyed by recording medium conveying means.

[0510] If a drive signal is supplied from drive signal supply means notshown to liquid discharge means on the carriage, the recording liquid isdischarged from the liquid discharge head to the recording medium, inaccordance with this signal.

[0511] Also, the liquid discharge apparatus of this embodiment has amotor 111 as a drive source for driving the recording medium conveyingmeans and the carriage, gears 112, 113 for transmitting a motive powerfrom the drive source to the carriage, and a carriage shaft 115. By thisrecording apparatus as well as the liquid discharge method carried outwith the recording apparatus, the recorded matter of good image qualitycould be obtained by discharging the liquid onto a variety of recordingmedia.

[0512]FIG. 29 is a block diagram of the whole device for performing theink discharge recording with the liquid discharge method and the liquiddischarge head according to the present invention.

[0513] The recording apparatus receives the print information as acontrol signal from a host computer 300. The print information is savedtemporarily in an input interface 310 inside the printer, and at thesame time converted into processible data within the printer, and inputinto a CPU 302 which is also used as head drive signal supply means. TheCPU 302 processes data entered into the CPU 302, using a peripheral unitsuch as RAM 304, and based on a control program stored in a ROM 303, forconversion into the print data (image data).

[0514] Also, the CPU 302 creates the drive data for driving a drivemotor which moves the recording sheet and the recording head,synchronously with the image data, to record the image data at anappropriate position on the recording sheet. The image data and themotor drive data are transferred via a head driver 307 and a motordriver 305 to the head 200 and the drive motor 306, each being driven ata controlled timing to form the image.

[0515] The recording media applicable to the recording apparatus, towhich the liquid such as the ink is attached, may include varioussheets, or an OHP sheet, plastic materials for use with the compact diskor ornamental plate, cloths, metal plate such as aluminum or copper,leather materials such as cowhide, pigskin, and artificial leather,woods such wood and plywood, bamboo, ceramic materials such as tile, andthree-dimensional structure such as sponge.

[0516] Also, the above recording apparatuses may include printers forprinting on various sheets or the OHP sheet, plastic printers forrecording on the plastic plate, such as compact disk, metal printers forrecording on the metal plate, leather printers for recording on theleather, wood printers for recording on the wood, ceramic printers forrecording on the ceramic material, recorders for recording on thethree-dimensional mesh structure such as sponge, and textile printingmachines for printing on the cloths.

[0517] Also, the discharge liquids for use with these liquid dischargeapparatuses may include those in accordance with the recording media orconditions.

[0518] <Recording Apparatus>

[0519] An example of an ink jet recording system for performing therecording on the recording medium, using a liquid discharge headaccording to this invention as the recording head will be given below.

[0520]FIG. 30 is a typical view for explaining the constitution of theink jet recording system using the liquid discharge head 201 to whichthis invention is applicable, as previously described.

[0521] The liquid discharge head in this embodiment is a full-line typehead having arranged a plurality of discharge ports at an interval of360 dpi over the length corresponding to the recordable width of therecording medium 150, four heads corresponding to four colors of yellow(Y), magenta (M), cyan (C), and black (Bk) being secured and supported,in parallel to each other, in a holder 202 at a predetermined intervalin an X direction.

[0522] To each of these heads, a signal is supplied from a head driver307 constituting drive signal supply means, and each head is drivenbased on this signal.

[0523] Each head is supplied with four color inks of Y, M, C and Bk, asthe discharge liquid, from the ink vessels 204 a to 204 d. Note thatnumeral 204 e is a bubbling liquid vessel in which the bubbling liquidis stored, wherein the bubbling liquid is supplied from this vessel toeach head.

[0524] Also, under the heads, head caps 203 a to 203 d having the inkabsorbing members such as sponge disposed inside are provided, whereinthe head can be subjected to maintenance by covering the discharge portsof the heads, when not used for recording.

[0525] Numeral 206 is a conveyer belt constituting conveying means forconveying various recording media as described in the previousembodiment. The conveyer belt 206 is looped around a predefined path viavarious rollers, and driven by a driving roller connected to the motordriver 305.

[0526] In the ink jet recording system of this embodiment, apreprocessing unit 251 and a postprocessing unit 252 for performingvarious processings on the recording medium before and after recordingare provided upstream and downstream of the recording medium conveyingpath, respectively.

[0527] The preprocessing and postprocessing are varied in the processingcontent, depending on the type of recording medium or the kind of inkfor use in recording, but for the recording media such as metal,plastic, or ceramics, for example, the preprocessing to apply theultraviolet ray and ozone is performed by activate the surface, therebyimproving the adherent property of ink. Also, for the recording mediaprone to generate static electricity such as plastic, the dirt may beeasily deposited on the surface due to static electricity, so thatexcellent recording may be prevented. Thus, by eliminating the staticelectricity from the recording medium, using an ionizer, as thepreprocessing, the dirt should be removed from the recording medium.Also, when the cloths are used as the recording medium, thepreprocessing to attach a substance selected from alkaline material,water soluble material, synthetic high polymer, water soluble metallicsalt, urea and thiourea to the cloths may be made, from the viewpointsof stain prevention and higher degree of exhaustion. The preprocessingis not limited thereto, but may be setting the temperature of therecording medium to an appropriate temperature.

[0528] On the other hand, the postprocessing may include a fixingtreatment for promoting the fixing of ink onto the recording mediumhaving the ink attached thereon, and washing the processing agentattached and unreacted in the preprocessing.

[0529] While in this embodiment a full-line head was used as the head,it will be appreciated that a small head such as those previouslydescribed may be conveyed in a width direction of the recording medium.

[0530] <Head Kit>

[0531] A head kit having a liquid discharge head according to thepresent invention will be described below.

[0532]FIG. 31 is a typical view of the head kit.

[0533] The head kit as shown in FIG. 31 houses, within a kit container501, a head 510 having an ink discharge portion 511 for discharging theink to which the invention is applied, an ink vessel 520 which is aliquid vessel integral with or separable from the head, and inkrefilling means for refilling the ink into this ink vessel with the inkheld.

[0534] When the ink is consumed, it is only necessary to insert a partof an insertion portion (such as a needle) 531 of the ink refillingmeans into an atmosphere communicating opening 521 of the ink vessel, aconnecting portion with the head, or a hole opened on the wall of theink vessel, and refill the ink within the ink refilling means into theink vessel via this insertion portion.

[0535] In this way, by accommodating the liquid discharge head accordingto this invention, the ink vessel, and the ink refilling means withinone kit container, as a kit, the ink can be easily refilled into the inkvessel immediately, as previously described, even if the ink isconsumed, whereby the start of recording can be effected promptly.

[0536] While in the head kit of this embodiment, ink refilling means isincluded. It will be appreciated that the head kit may have no inkrefilling means but comprise an ink vessel of separable type having theink filled, and a head housed within the kit container 510.

[0537] While ink refilling means for refilling the ink into the inkvessel is only shown in FIG. 31, it will be appreciated that bubblingliquid refilling means for refilling the bubbling liquid into a bubblingliquid vessel may be accommodated within the kit container.

EXAMPLES

[0538] The examples for the supply of liquid into the liquid dischargehead, or the pressure recovery, will be described below. Each means forthe supply of liquid or the pressure recovery as hereinafter describedmay be constituted integrally with the liquid discharge head, orprovided outside the liquid discharge head. Also, use of one flowpassage or two flow passages will be possible.

Example 1

[0539]FIGS. 56 and 57 are views showing the overview of the presentinvention.

[0540]FIG. 56 is a system configurational view for supplying two liquidsto the head H using two liquids, as previously described, and FIG. 57 isa typical view of an integral head system with a whole system mounted onthe head, though the fundamental system configuration is the same asthat of FIG. 56. Also, FIG. 61 shows a block diagram of the wholesystem.

[0541] First, the whole system will be described with reference to FIG.60. Note that the first liquid and the discharge liquid are the same,and the second liquid and the bubbling liquid are the same in thisfigure.

[0542] A liquid discharge portion 453 of the head 200 is the same asthat shown in FIG. 22, wherein a first discharge liquid supply passage20 supplied with the first liquid is connected with a supply tube 451,and a second supply passage supplied with the second liquid is connectedwith a supply tube 452. The first liquid side is connected via thesupply tube 451 to a check valve SV1, and further connected through thecheck valve SV1 to a valve V12. Further, the supply tube 451 is branchedafter the valve V12, to connect to a pump P1 and a valve V11, afterwhich the branches of the supply tube 451 passing in parallel areunited, to connect to a first liquid (or discharge liquid) tank. Thefirst liquid is supplied to the head 200 through this passage.

[0543] A second liquid supply passage 21 to which the second (bubblegeneration) liquid of the liquid discharge portion 453 for the head 200is supplied is connected with a supply tube 452, which is passed via acheck valve SV2, a deaerator D, a valve V22, and branched to connect toa valve V21 and a pump P2, after which the branches of the supply tube452 passing in parallel are united, to connect to a second liquid (orbubbling liquid) tank. The second liquid is supplied to the head 200through this passage.

[0544] While one of two liquids is the recording liquid for use inprinting, and the other is the bubbling liquid superior in the bubblegeneration characteristics, it will be appreciated that one may be therecording liquid, and the other may be the liquid with no or lesscoloring material, wherein the mixture liquid may be discharged, inanother embodiment.

[0545] Each function of the system configuration as above will bedescribed in respect of FIG. 60, and also with reference to the blockdiagram of FIG. 61.

[0546] The check valves SV1, SV2 may be basically the same. They allowthe liquid to flow in one direction, but not in opposite direction, orwill give rise to a much greater flow resistance than that in the flowdirection. In this example, they allow for the flow in a direction ofsupplying the liquid from the tank to the liquid discharge head, andinhibits the flow in opposite direction.

[0547] The deaerator D has the function of removing the gas componentdissolved in the second liquid (bubbling liquid) to be supplied to theliquid discharge head or the liquid discharge portion, from the secondliquid, via a gas permeable membrane, owing to a pressure differenceproduced by the vacuum or low pressure. This deaerator D can be placedanywhere in the liquid supply passage (except for the pump P2) from thesecond liquid tank to the liquid discharge head, or the liquid dischargeportion.

[0548] The valves V11, V12, V21 and V22 have, in addition to thefunction of permitting or inhibiting the supply of liquid from the twoliquid tanks to the head or liquid discharge portion, by the opening orclosing operation, the function for the recovery operation of feedingthe liquid to the head by closing the valves V11, V21 and allowing thepumps P1, P2 to feed the liquid to the head or liquid discharge portion.In this example, the pumps P1, P2 can be operated simultaneously orindependently.

[0549] While one of two liquids is the recording liquid for use inprinting, and the other is the bubbling liquid superior in the bubblegeneration characteristics, it will be appreciated that one may be therecording liquid, and the other may be the liquid with no or lesscoloring material, wherein the mixture liquid may be discharged, inanother embodiment.

[0550] Herein, the detailed constitution and operation of each portionwill be described below.

[0551]FIG. 32A is an exploded perspective view showing the constructionof a check valve, and FIG. 32B is a cross-sectional view. FIGS. 34A and34B are typical views of the embodiment in which a check valve isprovided within each of the flow passages for the bubbling liquid andthe discharge liquid, wherein FIG. 34A is in the normal state and FIG.34B is in the discharge state. Also, FIG. 35 illustrates the negativebalance of two liquids in the embodiment using the check valve. Pa is apressure within a tube 403 and Pb is a pressure within a tube 401,wherein the flow rate is represented when this balance is different.

[0552] The effects of the check valve will be described below.

[0553] The check valve as shown in FIG. 32A has a plate-like valvemember 402 provided with a cross cut line 404 made of an elastic rubbersandwiched between the tubes 401 and 403, thus having directionality forthe liquid flow, while the check valve as shown in FIG. 32B, like thatof FIG. 32A, has a plate-like valve member 402 provided with a slit 405sandwiched between the tubes 401 and 403, permitting the liquid flow ina direction from a to b with the movement of a central deformationportion of the plate-like valve member 405, and inhibiting the liquidflow in the opposite direction. These check valves have thedirectionality for the liquid flow, and the feature of allowing theliquid to flow in a direction from the flow passage a of the slendertube 403 to the flow passage b of the thicker tube 401, while preventingthe flow in a direction from the flow passage b of the thicker tube 401to the flow passage a of slender tube 403.

[0554] In FIG. 32C, a variation example of FIG. 32B is shown, wherein aslit 405 is doubly disposed along the external periphery of a valvemovable member 4052, with the complicate geometry of the slit 405 of theplate-like valve member 402 (see FIG. 33). Therefore, the area betweenthe slits is a valve spring portion 4050, whereby the valve operationcan be effected with a slight pressure difference, because thedeformable spring portion 4050 can be longer than that shown in FIG.32B. Further, the slit is of the double structure, so that the flowresistance becomes small when the liquid flow rate is great.

[0555] In FIG. 32D, a variation example of FIG. 32C is shown, wherein arib 4051 is provided to encircle the inner diameter of tube at thecontact portion between the inner side of slender tube 403 and the valvemovable portion 4052. In combination of these, the valve spring portion4050 is always subject to a deformation stress, resulting in the closercontact between the valve movable portion 4052 and the rib 4051 toprevent the mixture or diffusion of liquid.

[0556] This rib 4051 may be made of the same material as the tube 403,integrally therewith, but if it has higher elasticity, the much closercontact can be effected.

[0557] In this embodiment, as shown in FIGS. 34A and 34B, check valvesB₁, B₂ are provided in the flow passages via the supply tube 406 in adirection of liquid flow from the tank T₁, T₂ to the head H as in FIGS.22 and 54, respectively. A check valve B₁ is connected to the supplypassage 20 (FIG. 22, FIG. 54), and a check valve B₂ is connected to thesupply passage 21 (FIG. 22, FIG. 54), via the supply tube, leading tothe liquid chambers 15, 17, respectively. Normally, since a negativepressure is generated within the tank of each liquid, the liquid holds ameniscus at the discharge port of the head, so that the flow of liquidstands still. In the figure, P1 is a pressure of the ink tank, P₂ is apressure of the bubbling liquid tank, and P₃ is a pressure at the nozzleportion of head H (FIG. 34A).

[0558] However, if the liquid is discharged from the head H with theheat applied to the heating element (see first heating element 2), ameniscus is produced at the nozzle portion of head in discharging, atwhich portion a greater negative pressure is generated than that of thetank, resulting in P₁>P₃, P₂>P₃, whereby the liquid by the amount usedfor discharging is supplied through the check valves B₁, B₂ from thetank T to the head H (FIG. 34B).

[0559] Also, even at P₁=P₂ and P₂=P₃, since the flow passage issubstantially disrupted by the check valve, the mixture or diffusion oftwo liquids when left away for a long time can be prevented, but withthe check valve as shown in FIG. 32D, even at P₁=P₂ and P₂=P₃, since thevalve movable portion 4052 and the rib 4051 are pressed together, thedisrupted state can be maintained in spite of more or less vibration ordispersion in the pressure difference, whereby the liquid mixture ordiffusion can be prevented more stably.

[0560] Herein, the characteristics of the check valve is shown in FIG.35. With such characteristics, even if there is a difference in negativepressure between each liquid tank, the discharge ratio of two liquids(ratio of consumption) is easily maintained at constant and wellbalanced, so that the stable discharge can be made, and the mixture oftwo liquids at this valve portion can be prevented. In particular, thevalve can be closed with a pressure difference below a point P₁ by therib 405 of FIG. 32D. Also, the level of P₁ can be defined in accordancewith the height of rib 4051. That is, P₁ can be raised with greaterheight of rib 4051, to prevent the mixture or diffusion of two liquidsmore surely.

[0561] In particularly, in FIG. 32C, since the spring portion 4050 canbe lengthened, the slant of FIG. 35 can be increased, resulting inenhanced response of valve opening to pressure difference or flowproperty, with suppressed dispersion in the characteristics.

[0562] Also, in FIG. 32D, the valve opening can be suppressed up to a P₀level in the area P_(b)<P_(a) of FIG. 35, whereby the liquid mixture dueto the dispersion factors as previously described can be prevented.Further, by changing the parameters such as the height of rib 4051, thevalue of P₀ can be controlled.

[0563] In this embodiment, an experiment was made by setting thediameter of valve movable portion to about 1 to 5 mm, the thickness ofplate-like valve member 402 to 0.005 to 0.05 mm, and the width of slit405 to 0.005 to 0.1 mm, so that the slant of liquid flow rate to thepressure in FIG. 35 could be increased and the excellent characteristicscould be obtained. Also, the flow of about 5 to 20 mmAq could berealized at P₀, whereby the opening and closing response could beimproved while preventing the liquid mixture.

[0564] The operation in FIGS. 34A and 34B will be described below ingreater detail. For the pressure P₁ of an ink tank T1 and the pressureP2 of a bubble generation tank T2, 0≧P₁, P₂≧−200 mmAq. Note that apositive pressure tank not exceeding the value of P₀ can be used withthe rib 4051.

[0565] The pressure P₃ within the liquid chamber and nozzle portion ofthe head H is substantially invariable, unless the liquid is moved, andautomatically maintained at a value (P₃≧P₁, P₂) equal to or slightlygreater than the tank pressures P₁, P₂ with the characteristics of thevalve, not causing the liquid mixture or movement (state of FIG. 34A).However, if the liquid is discharged from the nozzle, the state of FIG.34B results. That is, since the meniscus at the discharge port of nozzleis retracted toward the nozzle to an extent corresponding to thedischarged liquid amount, the capillary force is produced correspondingto the shape of the nozzle. Due to this force, the meniscus begins toreturn to the discharge port, while a great negative pressure isgenerated in the nozzle and the liquid chamber.

[0566] The negative pressure within the liquid chamber is determined bythe capillary force, and smaller than the tank internal pressure, i.e.,in a range from −250 to 6000 mmAq. Such a wide range resulted from thearea and peripheral length of the discharge port and nozzle to producethe capillary force.

[0567] While in this example, the check valve was used in both supplypassages for the head using two liquids, it will be appreciated that thecheck valve may be used in either of them to prevent the liquid mixtureor diffusion.

[0568] Furthermore, when the check valve is used for both supplypassages, the check valve having different characteristics is used foreach supply passage, whereby the ratio of the exhausted amount ofbubbling liquid to that of discharge liquid can be controlled. That is,in the characteristics of the check valve as shown in FIG. 35, if thecheck valve having a different slant of pressure to flow rate is usedfor each of the supply passages of two liquids, the exhausted amount ofeach liquid is substantially in proportional relation at the ratiobetween its slant constants. For example, when the consumed ratio of thedischarge liquid to the bubbling liquid is made 10 to 11, the checkvalves having different characteristics with the ratio of the slantconstants of 10 to 11 may be used.

[0569] Further, the check valve, which allows for the flow of liquidonly in one direction, can prevent the diffusion of two liquids when notprinting.

[0570] While in this embodiment, the head of two liquids was described,it will be appreciated that in the head of one flow passage, the checkvalve may be also used in the flow passage to prevent the back wave whenthe bubble disappears, and effect the stable discharge.

[0571] While the check valve of the shape as shown in FIG. 32A and madeof silicon rubber was used, it will be appreciated that an active valveactivated by the bubble generation/bubble disappearance of bubble,bimetal or electrostatic adsorption, as shown in FIG. 32B or FIGS. 36Ato 36C, may be used. The materials may include the resin, metal, andsolvent resistant substance. The check valve may be formed integrallywith the separation wall by electrocasting. FIGS. 36A to 36C show avalve member 408 which is used in the liquid passage, having the valvefeature of permitting the liquid flow in the direction of the arrow, aswell as a check valve function and an active valve function in such thata bubble 408 is produced by generating the bubble in the liquid in theliquid passage 406 by heating of a heating element 407, as shown in FIG.36B, and then the valve is opened by attracting the valve member 408owing to a negative pressure when the bubble disappears, as shown inFIG. 36C, whereby the flow resistance in this portion can be extremelyreduced in the open state, resulting in a greater supply rate of liquid,which is preferable for the fast printing.

[0572]FIG. 37 is a typical diagram of this example having a check valvein the flow passage into a liquid chamber separable type color head.

[0573] The ink is supplied to the first flow passage within the head,for each color of C (cyan), M (magenta), and Y (yellow), with the checkvalves B₁ in the supply passages from the tanks T₁ to T₃. Also, thebubbling liquid is supplied to the second flow passage, with the checkvalves B₂ in the supply passages from one tank T₄.

[0574] With this constitution, it is unnecessary to use the identicalnumber of bubbling liquids in the multi-color tank/head, which ispreferable for the miniaturization of the apparatus or the reduced cost.

[0575] Thus, even if there is a negative pressure difference in eachtank, the bubbling liquid can be supplied from the common tank, withoutbeing influenced by the negative pressure difference, because the checkvalve is used in the supply passage to prevent the liquid movementbetween the tanks, as previously described, resulting in the stabledischarge.

[0576] Also, since the liquid mixture or diffusion can be prevented, themulti-color inks can be used without color mixture or diffusion ofliquids.

Example 2

[0577]FIG. 38 is a typical diagram of an example wherein a pressure pumpfor the pressure recovery is provided in each supply passage to a liquiddischarge head of the present invention.

[0578] In the head of two liquids according to the present invention,since it is difficult to discharge the first liquid (discharge liquid)and the second liquid (bubbling liquid) in respective amounts asrequired in the suction recovery from the discharge ports, theindependently controlled recovery can be effected by using a separatepump for supplying the liquid in a respective supply passage.

[0579] Also, in the liquid discharge head of the present invention, whenvarious inks such as a highly viscous ink or solid ink can be used, therecovery unit may be clogged or fixed in the conventional suctionrecovery system of the main unit, depending on the kind of ink, wherebyit is necessary to design these in view of the ink.

[0580] When the head is exchanged and other colors or kinds of the inkare used, the deterioration may occur within the recovery system bycombination of used inks.

[0581] Accordingly, in this example, the pressure recovery of the liquiddischarge head H is performed using a pressure pump P, and anycomplicate mechanism in the recovery system of the main unit wasdispensed with.

[0582] The pressure pump may be a tube pump, an oscillating flap, abubble jet (BJ) pump or an adjustable vane small pump.

[0583] In the liquid discharge head of two flow passages, one pressurepump may be provided for each flow passage, but one pump may be commonlyused to pressurize two flow passages, as shown in FIG. 39. FIG. 39 is aview of a BJ pump which transports the liquid by rotating a propeller409 b with a pressure produced by bubble generation of the liquid causedby heating of the heat generating members 410, and rotating a propeller409 a attached coaxially, in which case this pump, the discharge liquidfor use in the two liquid type head can be transported by this pump,using the bubbling liquid in a second liquid passage 412. Also, it canbe used for one liquid type.

Example 3

[0584]FIGS. 40A and 40B are views for explaining a third example of thepresent invention, wherein FIG. 40A is a perspective view, and FIG. 40Bis a cross-sectional view.

[0585] In FIGS. 40A and 40B, on a carriage 601 are disposed a liquiddischarge head 602, a liquid vessel 603 for storing the dischargeliquid, a liquid vessel 604 for storing the bubbling liquid, and a tubepump 605.

[0586] The carriage 601 is for example a carriage HC of the recordingapparatus as shown in FIGS. 63A and 63B, and as previously describedwith the discharge principle, and is reciprocated in the width direction(sub-scan direction) A of the recording medium such as the recordingsheet which is conveyed by recording medium conveying means, while beingsupported around the shafts 601C.

[0587] The discharge head 602 is a head having the first liquid flowpassage (discharge liquid flow passage) communicating to the dischargeport and the second liquid flow passage (bubbling liquid) containing thebubble producing area, for example, as described in the aboveembodiment. The first liquid flow passage is connected via a tube 603 ato the liquid vessel 603, and the second liquid passage is connected viaa tube 604 a to the liquid vessel 604. On the liquid vessel side of eachtube 603 a, 604 a, the one-way valves 603 b, 604 b are provided to allowthe liquid to flow from the liquid vessel to the head but prevent thereverse flow.

[0588] Between the liquid discharge head 602 and the liquid vessels 603,604, a tube pump 605 using the above tubes 603 a, 604 a is provided,thereby constituting liquid transporting means. This tube pump 605 iscomprised of a rotor 605 a having a plurality of rollers 605 b on thecircumference and a pan 605 c for pressing the rotor 605 a against thetube, as shown in FIG. 40B. This pan 605 c is curved along a roller faceof the rotor 605 a. This tube pump 605 has the tubes 603 a, 604 adisposed between the rotor 605 a and the pan 605 c, the tube beingdeformed by pressing the rotor 605 a against the pan 605 c, therebyrotating the rotor 605 a to feed the liquid into the head.

[0589] Also, the rotor 605 a is provided with a movable bearing 605 d,which can adjust the force pressing the rotor 605 a against the pan 605c freely. Thereby, the tubes 603 a, 604 a are fully compressed, as shownin FIG. 41A, allowing for the liquid supply of constant liquid amount inaccordance with the rotation of the rotor 605 a, or the tubes are notfully closed, as shown in FIG. 41B, giving rise to the flow resistance,to prevent the liquid supply from occurring with a greater pressure thannecessary. For example, if the tube 604 a (for bubbling liquid) isplaced in a state as shown in FIG. 41B, the liquid can be supplied,while adjusting the pressure balance for the supply of discharge liquidto the first liquid flow passage and the supply of bubbling liquid tothe second liquid flow passage.

[0590] In the recovery device with the above constitution, when the headrecovery is performed, the carriage 601 is first moved to a homeposition for effecting the recovery operation (e.g., Home Position), thetube pump 605 is operated, while a cap remains attached on the dischargeface of head, to supply the discharge liquid and the bubbling liquid tothe first and second liquid flow passages, respectively. In this way,the liquid is supplied to each liquid flow passage to perform the headrecovery. Note that the reverse flow of liquid caused by a pressuredifference after the recovery operation will not occur owing to theprovision of one-way valves 603 b, 604 b.

[0591] One example of transmitting the drive at the home position of thetube pump is typically illustrated in FIG. 42. In the same figure,position A is the home position, at which a drive motor 610 for drivingthe tube pump is provided. A first gear 612 is provided on a drive shaftof the drive motor 610, a driving force obtained from this first gearbeing transmitted to a second gear 613, and via a clutch 614 to a thirdgear 615. On the other hand, a fourth gear 616 is provided around arotational shaft of the tube pump 605 on the carriage 601, whereby whenthe carriage is moved from position B to position A which is the homeposition, the fourth gear 616 is meshed with the third gear 615 totransmit the driving force from the drive motor 610 to the tube pump605.

[0592] At the home position, the cap 611 is provided, whereby when thehead recovery is performed, the discharge face of head is capped withthis cap 610, so that the drain liquid from the discharge ports isexhausted through this cap 610 in driving the tube pump.

[0593] As a system different from the drive system as shown in FIG. 42,a drive motor 621 for driving the tube pump may be provided on thecarriage, for example, as shown in FIG. 43. In this case, the drivemotor 621 is connected via a flexible cable 623 to a control unit 620 onthe main body of the apparatus, and driven based on a control signalfrom the control unit 620.

[0594] While in the head of two liquid flow passages such as the liquiddischarge head 602 as above described, since various liquids havingdifferent viscosities can be discharge, as previously described with thedischarge principle, it is desirable to use the above-cited tube pumpcapable of freely adjusting the recovery amount or the liquid transportspeed to cope with a variety of kinds of inks, it should be noted thatother pumps than this tube pump may be employed such as a cylinder pumpor a diaphragm pump.

Example 4

[0595] While in the above example 3, the tube pump is provided on thecarriage, it should be noted that the tube pump may be provided on amain unit of the recording apparatus.

[0596]FIGS. 44A and 44B are views for explaining a fourth example,wherein FIG. 44A is a perspective view and FIG. 44B is a cross-sectionalview. In the figure, like numerals are attached to the same componentsas those of the recovery device of example 3, and the explanation ofthose components is omitted.

[0597] The recovery device of this example has a liquid discharge head602 mounted on a carriage 601 a supported around the shafts 601 c andmoved along the direction A, and the liquid vessels 603, 604 for thesupply of liquid via the tube to the liquid discharge head 602 mountedon a carriage 601 b. A connecting member (not shown) is used for theconnection with these carriages 601 a, 601 b.

[0598] The spacing between the carriages 601 a, 601 b may be largeenough to allow a tube pump 605 to be moved between the liquid dischargehead 602 and the liquid vessels 603, 604 at the home position, when inthe recovery operation. It will be appreciated that the spacing betweenthese carriages 601 a, 601 b may be provided only for the recoveryoperation, since they are unnecessary during the other operation(recording operation).

[0599] In the recovery device with the above constitution, in performingthe head recovery, the carriages 601 a, 601 b are moved to the recoveryposition (or home position) for the recovery operation. If the carriages601 a, 601 b are moved to the recovery position, the tube pump 605slides or rises from below, so that the tube is pressed against a pan bya roller. And the discharge face of head is capped, and the tube pump605 is driven to supply the discharge liquid and the bubbling liquid tothe first and second liquid flow passages, respectively, so that thedrain liquid from the discharge ports is exhausted through this cap.

Example 5

[0600] While the examples 3, 4, the tube pump is provided between theliquid discharge head and the liquid vessels to feed the liquid intoeach liquid flow passage (liquid transporting means), it should be notedthat the liquid may be fed from the liquid vessel to each liquid flowpassage by feeding the air into the liquid vessels by means of the tubepump (liquid transporting means).

[0601]FIGS. 45A and 45B are views for explaining a fifth example of thisinvention, wherein FIG. 45A is a perspective view and FIG. 45B is across-sectional view. A recovery device of this example is the same asin the above example 1, except that the air is fed into the liquidvessel by the tube pump. In the figure, like numerals are attached tothe same components as those of the recovery device of the example 3,and the explanation of those components is omitted.

[0602] On a carriage 601, a liquid discharge head 602, liquid vessels603, 604, and a tube pump 605 are mounted. The liquid vessels 603, 604are provided with the tubes 603 c, 604 c for feeding the air into thevessels, respectively, which constitute the tube pump 605.

[0603] In this recovery device, if the tube pump 605 is driven, the airis fed via the tubes 603 c, 604 c into the liquid vessels 603, 604. Ifthe air has been fed into the liquid vessels 603, 604, the liquid isfed, by an amount corresponding to the amount of the air which has beenfed, from the liquid vessels 603, 604 via the tubes 603 a, 604 a to theliquid discharge head 602. In this way, the liquid is fed from theliquid vessel into each liquid flow passage by feeding the air into theliquid vessels by means of the tube pump, to effect the head recovery.

[0604] In the recovery device of this example, since it is not necessaryto have the tube between the liquid discharge head 602 and the liquidvessels 603, 604, the liquid vessels 603, 604 may be attached to theliquid discharge head 602 (e.g., head cartridge), for example, as shownin FIG. 46A. Thereby, the total size can be reduced. In this case,one-way valve is not provided, but the reverse flow is prevented bypressing the rotor against a pan in the tube pump 605 without drivingthe tube pump 605. In this state, the recording is performed bydischarging the liquid.

[0605] It will be appreciated that since the tube pump transports theair, the tubes 603 c, 604 c provided on the pump itself may be pressed,at one end thereof, onto an atmosphere communicating opening provided ona side wall of liquid vessel.

Example 6

[0606] While in the above example 5, the tube pump was provided on thecarriage, it should be noted that the tube pump may be provided in amain unit of the recording apparatus.

[0607]FIGS. 47A and 47B are views for explaining a sixth example,wherein FIG. 47A is a perspective view and FIG. 47B is a cross-sectionalview. In the figure, like numerals are attached to the same componentsas those of the recovery device of example 4, and the explanation ofthose components is omitted.

[0608] In this example, a tube pump 605 is not mounted on the carriage601, but provided on a main unit of the recording apparatus, and slidesor rises from below upon the recovery operation, so that the tubes 603c, 604 c are sandwiched between a roller of the tube pump and a pan.

[0609] In a recovery device with the above constitution, when performingthe head recovery, a carriage 601 is first moved to a recovery position(or home position) for the recovery operation. If the carriage 601 ismoved to the recovery position, the tube pump 605 slides or rises frombelow, so that the tube is pressed onto the pan by the roller. And thedischarge face of head is capped with a cap, and the tube pump 605 isdriven to supply the discharge liquid and the bubbling liquid into thefirst and second liquid flow passages, respectively, so that the drainliquid from the discharge ports is exhausted through the cap.

[0610] In the recovery device of this example, as in the above example4, since it is not necessary to have the tube between the liquiddischarge head 602 and the liquid vessels 603, 604, the liquid vessels603, 604 may be attached to the liquid discharge head 602 (e.g., headcartridge), for example, as shown in FIG. 46B. Thereby, the total sizecan be reduced.

Example 7

[0611] While in the above examples, one tube pump was provided, itshould be noted that a tube pump may be provided for each vessel.

[0612]FIG. 51 is a diagram for explaining a seventh example of thepresent invention.

[0613] In this example, two tube pumps 1001, 1002 are used. A tube pump1001 is provided in a tube between a liquid discharge head 1000 and abubbling liquid vessel 1003, and a tube pump 1002 is provided in a tubebetween a liquid discharge head 1000 and a discharge liquid vessel 1005,so that the liquid can be supplied to each liquid flow passage,independently. Each tube pump 1001, 1002 is independently driven, andcontrolled via a switch 1005 from a drive control unit 1006. With thisconstitution, the supply of discharge liquid to a first liquid flowpassage and the supply of bubbling liquid to a second liquid flowpassage can be independently controlled. Further, the pressure balancefor the supply of liquid to each liquid flow passage can be controlledat will.

[0614] In this example, one-way valve is not provided, but the reverseflow is prevented by pressing a rotor against a pan in the tube pumpwithout driving the tube pump. In this state, the recording is performedby discharging the liquid.

Pump Example 1

[0615] While in the examples 3 to 6 as previously described, because thehead of two liquid flow passages allows various liquids having differentviscosities to be used, a tube pump capable of adjusting the recoveryamount or the liquid transport speed freely, corresponding to a varietyof inks was used, it will be appreciated that a pump with theconstitution as shown in FIG. 48 may be used, instead of this tube pump.

[0616] In FIG. 48, one-way valves 701, 702 are provided within atransport tube 700 for transporting the liquid (discharge liquid orbubbling liquid) or the air. An opening portion 703 is provided at apart of tube in the region segmented by the one-way valves 701, 702, anelastic wall 704 is provided to close up its opening in the openingportion 703. This elastic wall 704 is displaced between position A andposition B by a pressure regulator lever 705. A one-way valve 701 isprovided downstream, while a one-way valve 702 is provided upstream,both regulating the flow to an upstream direction.

[0617] In the pump with the above constitution, if the elastic wall 704is displaced from position A to position B by the pressure regulatorlever 705, the one-way valve 702 is closed, and the one-way valve 701 isopened, so that the liquid or air upstream of the one-way valve 701 isfed downstream of the one-way valve 701. On the other hand, if theelastic wall 704 is displaced from position B to position A by thepressure regulator lever 705, the one-way valve 701 is closed and theone-way valve 702 is opened, so that the liquid or air upstream of theone-way valve 702 is fed downstream of the one-way valve 702.

<Pump Example 2

[0618] While in the examples 5 and 6 as previously described, the liquidis fed from the liquid vessel to each liquid flow passage by feeding theair into the liquid vessel, a pump for pressurizing the liquid vessel aswill be described below may be used, instead of the tube pump.

[0619]FIGS. 49A to 49D are views of a pump using a displacement cam,schematically illustrating the pump operation. In the same figure, aliquid vessel 800 has an elastic wall 801, with an opening portion 803formed at a part (center) of the elastic wall 801. Over this openingportion 803, a sheet member 802 is provided to close up the opening.

[0620] In the pump with the above constitution, if the displacement cam804 is rotated, the opening portion 803 is closed up by the sheet member802, so that the elastic wall 801 is displaced inside the vessel. If theelastic wall 801 is displaced inside the vessel, the vessel ispressurized, so that the liquid from the liquid vessel is delivered intothe liquid discharge head (FIGS. 49A and 49B). If the displacement cam804 is further rotated to exceed the maximum displacement, a gap willoccur between the sheet member 802 and the opening portion 803, causingthe elastic wall 801 to return to its original position (FIGS. 49C,49D). In this way, if the displacement cam 804 is rotated to pressurizethe vessel, the liquid can be supplied.

<Pump Example 3

[0621] Besides the pump examples as above described, a pump fordelivering the liquid from the liquid vessel into each liquid flowpassage by feeding the air into the liquid vessel is shown in FIGS. 50Ato 50D.

[0622] In FIGS. 50A to 50D, an opening portion 901 is provided at a partof a side wall of a liquid vessel 900. A cap pump 902 has a cap 902 awhich can cover this opening portion 901, and can pressurize the liquidvessel 900 by pressing the cap 902 a against the wall to close up theopening portion 901, and pushing in a support rod 902 b for supportingthe central portion of the cap 902 a to deform the cap. The deformed capcan be reversed by hanging an edge end of the cap 902 a on a guide 903and pulling back the support rod 902 b (FIGS. 50C, 50D). In this way,the liquid can be supplied by pressing the cap 902 a against the wall tocover the opening portion 901 and deforming the cap to pressurize thevessel.

[0623] Using these pumps, it is possible to reduce the load of therecovery system of the main unit by performing the head recovery underthe pressure.

Example 8

[0624]FIGS. 52A to 52C are typical views of a head integrated with a caphaving a liquid holding member which is a waste ink reservoir, whereinFIG. 52A is a slide type, FIG. 52B is a rotation type, and FIG. 52C is aseparation type which has been integrated, and in FIGS. 52A to 52C, (a)shows the state of physical distribution, and (b) shows the state ofprinting.

[0625] Since the used liquid or ink is not limited by the recoverysystem of the main unit, like the pressure recovery of the example 2,the waste ink reservoir is disposed on the head side, and the use of anew waste ink reservoir, a cap and a blade for each head is enabled.

[0626] A way of attaching or detaching the slide type cap onto or fromthe head will be described below. FIGS. 53A to 53D are explanatory viewsillustrating the attaching or detaching of a slide type head cap 413onto a head 414.

[0627] The slide type head cap 413 of FIG. 52A is attached slidably in aslide groove of the head, and can take an attached state (a) where thehead 414 and the head cap 413 are coupled and a non-attached state (b).

[0628] The cap is put onto the face surface of the head during physicaldistribution (FIG. 53A), the head 414 being capped is mounted on acarriage 418 (FIG. 53B) at a home position (FIG. 53B), using a headsecuring lever 423, so that the cap lever 420 protruding from the capengages with a slide guide 417 provided on the printer unit (FIG. 53C).

[0629] When in use, a print signal is issued, and when the carriage 418is moved along a carriage shaft 422 from the home position into theprinting area (to the left in the figure), the cap lever 420 of the cap413 will slide within the slide groove of the head, so that the cap 413is removed from the face surface (FIG. 53D) to start the printing.Conversely, when the printing is ended, the carriage 418 is returned tothe home position from the state D to the state C of the same figure,and the cap is put on the face surface where the discharge ports of thehead are provided.

[0630] At the time of recovery, with the cap 413 retained on the face,or with the cap 413 slightly away from the face surface by moving thecarriage 418, the waste ink is received in the waste ink reservoir.

[0631] After the recovery, to remove the ink remaining on the facesurface with the blade, the blade operation can be performed in such amanner as to separate the cap from the face surface by moving the cap413 with a blade 421 provided on the cap 413.

[0632] The same method is applicable to other caps such as the rotationtype cap 415 and the separation type cap 416, without being limited tothe slide type.

[0633] Herein, the slide type is met with a smaller cap opening orclosing and operational area, and thus appropriate for the saving ofspace, the rotation type is simple in the mechanical design, and theseparation type allows for the reduced carriage weight.

[0634] In this example, for each head, a new cap, a waste ink reservoir,and a blade can be used, whereby the fixing problem of the recoverysystem of the main unit with the liquid ink can be avoided. Accordingly,the scope of selecting the used liquid ink can be extended.

[0635] Also, a variety of cartridges can be used in one main unit,whereby the inks of different colors or kinds can be used for theprinting.

[0636] In this example, the above head is of the structure having acheck valve, with the advantages thereof, which is applicable to thehead using two liquids or only one liquid as previously described in theembodiments of this invention, and more preferably implemented with thespecial liquid such as quick drying ink or high viscous ink.

Example 9

[0637]FIG. 54 is a typical diagram showing the structure where a valveis provided in a supply passage to the liquid discharge head of thisinvention.

[0638] Herein, the used valve will be described below. The principle isthat, like the opening and closing operation of the movable member asdescribed in FIGS. 36A to 36C, the opening and closing operation of thevalve can be made by development of a bubble caused by the heatingelement, but other principles for the opening and closing of valve canbe employed.

[0639] In FIG. 54, B₁ is a movable member within the liquid dischargehead, B₂ is a valve in the ink flow passage, and B₃ is a valve in thebubbling liquid flow passage, wherein these valves serve to supply theink and the bubbling liquid to the liquid discharge head, and are notdirectly involved in the discharge.

[0640] When the movable member B₁ is once turned off and closed, thevalves B₂, B₃ are displaced by the bubble produced by heating of theheat generating member, to open the flow passage.

[0641] The heat generating member of the movable member B₁ generates theheat to heat and generate the bubble in the the liquid, so that theliquid is discharge, while the heating energy of the valves B₂, B₃ isstopped, to close the valves at all times.

[0642] When the valves B₂, B₃ are closed, the flow passage issubstantially shut off with the displacement of the valve, so that theliquid is prevented from flowing in a direction opposite to thedischarge port direction, as the back wave in discharging, like thecheck valve. Also, the meniscus is produced after the dischargeoperation, the liquid is supplied from the tank, by the displacement ofthe valves B₂, B₃ which are opened by bubble generation or bubbledisappearance, with the extremely small flow resistance with the valve,whereby the refill can be smoothly conducted.

Example 10

[0643]FIG. 55 is a perspective view of a liquid discharge head of thepresent invention.

[0644] In FIG. 55, the discharge liquid is stored in a first liquidvessel 551, and the bubbling liquid predeaerated is stored in a secondliquid vessel 552. Note that the liquid vessel 552 is in the form of anenclosed cartridge such as an ink tank having a sealed flexible bag(having an aluminum layer).

[0645] The bubbling liquid is predeaerated before being filled into theliquid vessel 552. A way of deaeration is not particularly limited, butin this example, was made using NICEP SF-131LS manufactured by NittoDenko Corporation. Also, the conditions of deaeration area varied,depending on the composition of the bubbling liquid, but it issufficient that the dissolved gas in the liquid can be sufficientlydeaerated.

[0646] After the dissolved gas has been sufficiently deaerated, thebubbling liquid is filled in the liquid vessel 552.

[0647] In this constitution, two liquid flow passages of a liquid flowpassage for the discharge liquid and a liquid flow passage for thebubbling liquid are provided, but the liquid flow passage for thebubbling liquid is of a structure substantially enclosed, except for aslit of the movable member.

[0648] Also, in this constitution, the bubbling liquid having a water toethanol composition of 9 to 1 was used, but the bubbling liquid containsthe water of 20% or more by weight, and is preferably deaerated.

[0649] In this example, the stable discharge by the even bubblegeneration could be accomplished without the gas remaining in the liquidflow passage for the bubbling liquid.

Example 11

[0650]FIG. 56 is an exploded perspective view of a head according to thepresent invention, and FIG. 57 is an exploded perspective view of aliquid discharge head cartridge.

[0651] This constitution is provided with a deaeration system 554 fordeaerating the bubbling liquid behind the head of FIG. 23, as shown inFIGS. 56 and 57, the deaeration system 554 being placed between a liquidvessel 90 with the liquid filled in the head cartridge of FIG. 27 andthe liquid discharge head.

[0652] A liquid discharge head with the above deaeration system appliedwill be described below.

[0653]FIG. 58 is a cross-sectional view showing one constitutionalexample of the liquid discharge head to which the deaeration system isapplied.

[0654] In FIG. 58, a discharge port 18 for discharging the liquid, afirst liquid vessel 551 for storing the discharge liquid, a first liquidflow passage 14, communicating to the discharge port 18 and the liquidvessel 551, for conducting the discharge liquid stored within the liquidvessel 551 to the discharge port, a second liquid vessel 552 for storingthe bubbling liquid, a substrate 1 having a heat generating member 2provided, a second liquid flow passage 16, communicating to the liquidvessel 552, for conducting the bubbling liquid stored in the liquidvessel 551 to the heat generating member 2, a movable member 31 providedto separate the first liquid flow passage 14 and the second liquid flowpassage on the heat generating member 2, with the discharge port side asa free end and the opposite side as a fulcrum, displaced toward thefirst liquid flow passage 14 by the pressure of a bubble produced on theheat generating member 2, to communicate the first liquid flow passage14 with the second liquid flow passage 16, a separation wall containingthe movable member 31 and made of a material having high gas impermeableproperty such as metal or PVDF (polyvinylidenefluoride), and adeaeration system, provided between the second liquid flow passage 16and the liquid vessel 552, for deaerating the bubbling liquid storedwithin the liquid vessel 552 for the supply to the second liquid flowpassage 16, the deaeration system being comprised of a deaeration liquidsupply port 557 which is a joint portion with the second liquid flowpassage 16, a membrane 553 made of a material having high gaspermeability such as ethylene fluoride for permeating the gas from thebubbling liquid, a gas exhaust portion 555 for exhausting the gas fromthe bubbling liquid via the membrane 553, and a vacuum pump 556 forsucking the gas from the bubbling liquid.

[0655] The operation of the liquid discharge head with the aboveconstitution will be described below.

[0656] If the bubbling liquid stored within the liquid vessel 552 issupplied to the deaeration system 554, the gas exhaust portion 555 isplaced in a low pressure state by the vacuum pump 556 provided withinthe deaeration system 554, whereby the gas is sucked from the bubblingliquid via the membrane 553.

[0657] And the deaerated bubbling liquid is supplied via the deaerationliquid supply port 557 to the second liquid flow passage 16.

[0658] On the other hand, the discharge liquid stored within the liquidvessel 551 is supplied to the first liquid flow passage 14.

[0659] By heating of the heat generating member 2, a bubble is producedin the bubbling liquid, to cause the movable member 31 to be displacedto the first liquid flow passage 14, owing to a pressure by its bubble,so that the discharge liquid is discharged in the first liquid flowpassage 14 from the discharge port 18.

[0660] In the liquid discharge head as above described, the gas is notdissolved in the bubbling liquid, even when left away for a long time,and the dissolved gas is not deposited on the heat generating member dueto temperature elevation by repeating the heating and forming for thedischarge, resulting in the stable bubble generation state, with thestate discharge characteristics obtained.

Example 12

[0661] In this constitution, a pigment ink was used for the dischargeliquid. In the following, the composition of the pigment ink is listed.Carbon black 6 wt % Styrene-acrylic acid-ethyl acrylate copolymer 1 wt %(acid value 140, weight average molecular weight 8000) Monoethanolamine0.25 wt % Glycerine 9 wt % Thiodiglycol 7 wt % Ethanol 3 wt % Water76.75 wt %

[0662] The pigment ink is an ink having excellent anti-fastness, but isgreatly restricted by the kind or amount of dispersing agent, becausethe burnt deposits may occur on the heat generating member by heating ofthe heat generating member.

[0663] In the head of this invention, the mixture of the bubbling liquidand the discharge liquid is prevented by regulating the slit widtharound the movable member, but there is a possibility that the dischargeliquid may more or less mingle into the liquid flow passage for thebubbling liquid, due to the characteristics of two liquids for use, orthe mixture of two liquids when discharged or when left away for a longtime.

[0664] In this example, the bubbling liquid had the followingcomposition: Acetylenol  3 wt % Ethanol 20 wt % Water 77 wt %

[0665] By adding an active agent such as acetylenol, as the surfacestabilizer, the wettability of liquid on the heat generating member isincreased to prevent the burnt deposits from adhering thereto, but evenif the discharge liquid diffuses to the liquid flow passage for thebubbling liquid, to yield the burnt deposits on the heat generatingmember, the burnt deposits can be easily peeled by the external force ofthe bubbling liquid.

[0666] In the liquid discharge head as above described, the bubblegeneration as well as the discharging were stabilized. In particular, inthis example, the consumption amount of the bubbling liquid is reduced,and since the bubbling liquid is mixed at a ratio of about 10% to thedischarge liquid in discharging the liquid, acetylenol in the dischargedliquid is about 0.3%, whereby the liquid shot onto the recording mediumwill not blur too much.

[0667] Accordingly, it is possible to enhance the peeling ability ofburnt deposits, with the good print quality maintained, whereby thestable bubble generation and stable discharge can be accomplished,resulting in the higher image quality.

Example 13

[0668]FIG. 59 is a schematic view of a liquid discharge system providedwith all of a pressure pump, a check valve, a valve, a cap, a tank and adeaerator, and FIG. 60 is a schematic view showing the construction inwhich each mechanism is mounted on a liquid discharge head.

[0669] As shown in FIGS. 59 and 60, the whole system or head unit may beconstructed.

[0670]FIG. 61 is a block diagram showing the overall configuration ofthe liquid discharge system with the liquid discharge head. Also, FIG.62 is a flowchart showing a control procedure of the liquid dischargehead.

[0671] The control procedure of the liquid discharge system will bedescribed below.

[0672] The head is capped during physical distribution, with thebubbling liquid filled in the head. When in use, the head is mounted ona carriage (S1), the electrical power is turned on, the recoveryfunction is started, and the head recovery is performed in the order ofink and bubbling liquid, using a pressure pump and a valve (S2 to S4).

[0673] As previously described, the cap is separated away from the faceby moving the carriage, and the blade is exerted.

[0674] During printing, the valve is automatically opened and closed inaccordance with the print duty, to retain the supply balance (S5).

[0675] After printing, the carriage is returned to the home position,where the suction recovery is performed after the head is filled withthe bubbling liquid (S7), and the face surface is capped (S9).

[0676] The above examples involve a head structure of two flow passages,a liquid discharge head cartridge and a liquid discharge apparatus,which are obtained with the excellent effects. Also, they are applicableto the head of one flow passage which was partly described in theexamples.

[0677] Also, by having a check valve and a pressure pump at the sametime, the recovery can be more surely performed while the reverse flowof the liquid ink is prevented.

[0678] It is needless to say that the present invention is alsoapplicable to a side shooter type having the discharge port at aposition opposite the face of the heat generating member.

[0679] The present invention exhibits the following effects as follows,owing to the constitution as above described:

[0680] (1) In the liquid discharge head of one flow passage, thedischarge power is further stabilized, while the load on the recoverysystem of the main unit can be relieved.

[0681] (2) In the liquid discharge head of two flow passages, the supplybalance of two liquids can be kept to effect the stable discharge and toprevent the liquid mixture or diffusion.

[0682] (3) When using a special ink, the load on the recovery system ofthe main unit can be reduced.

[0683] (4) The liquids are independently supplied into the first liquidflow passage (discharge liquid flow passage) and the second liquid flowpassage (bubbling liquid flow passage), respectively, upon the recovery,so that the bubble or dirt will not remain in each liquid flow passagewithin the head. Also, since the liquid is discharged while the reverseflow of liquid in the liquid flow passage is prevented, the stability ofthe discharge performance for the liquid discharge head can bemaintained, and the reliability raised.

[0684] (5) When using a tube pump, the deformation amount of tube due tothe roller of tube pump can be varied between the first liquid flowpassage side and the second liquid flow passage side. For example, ifthe liquid is transported with the tube completely closed, on the firstliquid flow passage side, and with the tube not completely closed, onthe second liquid flow passage side, it is possible to prevent thesupply of liquid with a greater pressure than necessary, therebyeffecting the stable recovery operation.

[0685] (6) In a pump for forcefully feeding the liquid to the liquiddischarge head by pressurizing the liquid vessel, since the liquiddischarge head and the liquid vessel can be integrated (into cartridge),the reduced cost and size of the apparatus can be realized.

[0686] (7) Since the bubbling liquid to be supplied to the heatgenerating member is predeaerated, the second liquid vessel for storingthe bubbling liquid is of the closed type, and the separation wall forseparating between the first liquid flow passage having the dischargeliquid supplied and the second liquid flow passage having the bubblingliquid supplied has the gas impermeability, the gas is not contained anddissolved in the bubbling liquid to be supplied to the heat generatingmember.

[0687] (8) Since the deaeration means for deaerating the bubbling liquidis provided between the second liquid vessel and the second liquid flowpassage, even if the gas is contained in the bubbling liquid within thesecond liquid vessel, the bubbling liquid can be deaerated by deaeratingmeans, when supplied to the heat generating member, whereby no gas willbe contained in the bubbling liquid conducted to the heat generatingmember.

[0688] (9) Since the liquid for peeling the burnt deposits on the heatgenerating member was used as the bubbling liquid, the burnt depositscan be removed by the bubbling liquid, even if the discharge liquiddiffuses within the second liquid flow passage and the burnt depositsoccur on the heat generating member by heating of the heat generatingmember.

What is claimed is:
 1. A liquid discharge head comprising dischargeports for discharging the liquid, a bubble producing area for producingan air bubble in the liquid of liquid flow channels, and a movablemember, which is disposed toward said bubble producing area, anddisplaceable between a first position and a second position farther awayfrom said bubble producing area than said first position, the liquiddischarge head discharging the liquid in such a manner that said movablemember is displaced from said first position to said second position bya pressure due to a bubble produced in said bubble producing area, andsaid bubble is more greatly expanded downstream than upstream in adirection toward said discharge port, due to the displacement of saidmovable member, characterized by having a check valve disposed in aliquid supply passage leading to said liquid flow channels.
 2. A liquiddischarge head comprising discharge ports for discharging the liquid,liquid flow channels each having a heating element for applying heat tothe liquid to produce a bubble in said liquid, and a supply passage forsupplying the liquid onto said heating element from the upstream side ofsaid heating element along said heating element, and a movable member,provided toward said heating element, with a free end on the dischargeport side, for displacing said free end due to a pressure caused by saidbubble produced to conduct said pressure to the discharge port side,characterized by having a check valve disposed in said liquid supplypassage.
 3. A liquid discharge head comprising discharge ports fordischarging the liquid, a heating element for applying heat to theliquid to produce a bubble in said liquid, a movable member, providedtoward said heating element, with a free end on the discharge port side,for displacing said free end due to a pressure caused by said bubbleproduced to conduct said pressure to the discharge port side, and asupply passage for supplying the liquid onto said heating element fromthe upstream side thereof along the face of said movable member closerto said heating element, characterized by having a check valve disposedin said liquid supply passage.
 4. A liquid discharge head comprising afirst liquid flow channel communicating to a discharge port, a secondliquid flow channel having a bubble producing area for producing abubble in said liquid by applying heat to the liquid, and a movablemember, disposed between said first liquid flow channel and said bubbleproducing area, with a free end on the discharge port side, fordisplacing said free end toward said first liquid flow channel due to apressure caused by said bubble produced within said bubble producingarea to conduct said pressure to the discharge port side of said firstliquid flow channel, characterized by having a check valve disposed in aliquid supply passage leading to either one of said first and secondliquid flow channels.
 5. A liquid discharge head comprising a firstliquid flow channel communicating to a discharge port, a second liquidflow channel having a bubble producing area for producing a bubble insaid liquid by applying heat to the liquid, and a movable member,disposed between said first liquid flow channel and said bubbleproducing area, with a free end on the discharge port side, fordisplacing said free end toward said first liquid flow channel due to apressure caused by the bubble produced within said bubble producing areato conduct said pressure to the discharge port side of said first liquidflow channel, characterized by having a check valve disposed in a liquidsupply passage leading to said first and second liquid flow channels. 6.A liquid discharge head comprising: a grooved member having integrally aplurality of discharge ports for discharging the liquid, a plurality ofchannels for making up a plurality of first liquid flow channelsdirectly communicating to and corresponding to respective dischargeports, and a recess portion for constituting a first common liquidchamber for supplying the liquid to said plurality of first liquid flowchannels; an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and a separation wall, disposed between said grooved member andsaid element substrate, for composing a part of a wall for said secondliquid flow channel corresponding to said heating element, and having amovable member which is displaceable toward said first liquid flowchannel by a pressure due to a bubble produced at the position opposedto said heating element, characterized by having a check valve disposedin a liquid supply passage leading to either one of said first andsecond liquid flow channel.
 7. A liquid discharge head comprising: agrooved member having integrally a plurality of discharge ports fordischarging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tosaid plurality of first liquid flow channels; an element substratehaving a plurality of heating elements arranged for producing a bubblein the liquid by applying heat to the liquid; and a separation walldisposed between said grooved member and said element substrate, forcomposing a part of a wall for said second liquid flow channelcorresponding to said heating element, and having a movable member,which is displaceable toward said first liquid flow channel by apressure due to a bubble produced at the position opposed to saidheating element, characterized by having a check valve disposed in aliquid supply passage leading to said first and second liquid flowchannels.
 8. A liquid discharge head according to claim 5 or 7,characterized in that the check valve provided on the liquid supplypassage to said first liquid flow channel and the check valve providedon the liquid supply passage to said second liquid flow channel havedifferent characteristics.
 9. A liquid discharge head according to anyone of claims 1 to 7, characterized in that said check valve operateswith a pressure difference between liquids on both sides of said checkvalve.
 10. A liquid discharge according to claim 9, characterized bycomprising offset means for offsetting said pressure difference on whichsaid check valve operates.
 11. A liquid discharge head according toclaim 10, characterized in that said offset means is a rib which isprovided to be in contact with said check valve.
 12. A liquid dischargehead according to claim 6 or 7, characterized in that said check valveis formed integrally with said separation wall.
 13. A liquid dischargehead comprising discharge ports for discharging the liquid, a bubbleproducing area for producing an air bubble in the liquid of liquid flowchannels, and a movable member, disposed toward said bubble producingarea, which is displaceable between a first position and a secondposition farther away from said bubble producing area than said firstposition, the liquid discharge head discharging the liquid in such amanner that said movable member is displaced from said first position tosaid second position by a pressure due to a bubble produced in saidbubble producing area, and said bubble is more greatly expandeddownstream than upstream in a direction toward said discharge port, dueto the displacement of said movable member, characterized by having avalve for preventing the liquid on the side of said liquid flow channeland the liquid on the opposite side from said liquid flow channel frommixing within a liquid supply passage into said liquid flow channel. 14.A liquid discharge head comprising discharge ports for discharging theliquid, liquid flow channels each having a heating element for applyingheat to the liquid to produce a bubble in the liquid, and a supplypassage for supplying the liquid onto said heating element from theupstream side of said heating element along said heating element, and amovable member, provided toward said heating element, with a free end onthe discharge port side, for displacing said free end due to a pressurecaused by said bubble produced to conduct said pressure to the dischargeport side, characterized by having a valve for preventing the liquid onthe side of said liquid flow channel and the liquid on the opposite sidefrom said liquid flow channel from mixing within a liquid supply passageinto said liquid flow channels.
 15. A liquid discharge head comprisingdischarge ports for discharging the liquid, a heating element forapplying heat to the liquid to produce a bubble in said liquid, amovable member, provided toward said heating element, with a free end onthe discharge port side, for displacing said free end due to a pressurecaused by said bubble produced to conduct said pressure to the dischargeport side, and a supply passage for supplying the liquid onto saidheating element from the upstream side thereof along the face of saidmovable member close to said heating element, characterized by having avalve for preventing the liquid on the side of said liquid flow channeland the liquid on the opposite side from said liquid flow channel frommixing within a liquid supply passage into said liquid flow channel. 16.A liquid discharge head comprising a first liquid flow channelcommunicating to a discharge port, a second liquid flow channel having abubble producing area for producing a bubble in said liquid by applyingheat to the liquid, and a movable member, disposed between said firstliquid flow channel and said bubble producing area, with a free end onthe discharge port side, for displacing said free end toward said firstliquid flow channel due to a pressure caused by said bubble producedwithin said bubble producing area to conduct said pressure to thedischarge port side of said first liquid flow channel, characterized byhaving a valve for preventing the liquid on the side of said liquid flowchannel and the liquid on the opposite side from said liquid flowchannel from mixing within a liquid supply passage leading to either oneof said first and second liquid flow channels.
 17. A liquid dischargehead comprising a first liquid flow channel communicating to a dischargeport, a second liquid flow channel having a bubble producing area forproducing a bubble in said liquid by applying heat to the liquid, and amovable member, disposed between said first liquid flow channel and saidbubble producing area, with a free end on the discharge port side, fordisplacing said free end toward said first liquid flow channel due to apressure caused by the bubble produced within said bubble producing areato conduct said pressure to the discharge port side of said first liquidflow channel, characterized by having a valve for preventing the liquidon the side of said liquid flow channel and the liquid on the oppositeside from said liquid flow channel from mixing within a liquid supplypassage leading to said first and second liquid flow channels.
 18. Aliquid discharge head comprising: a grooved member having integrally aplurality of discharge ports for discharging the liquid, a plurality ofchannels for making up a plurality of first liquid flow channelsdirectly communicating to and corresponding to respective dischargeports, and a recess portion for constituting a first common liquidchamber for supplying the liquid to said plurality of first liquid flowchannels; an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and a separation wall, disposed between said grooved member andsaid element substrate, for composing a part of a wall for said secondliquid flow channel corresponding to said heating element, and having amovable member which is displaceable toward said first liquid flowchannel by a pressure due to a bubble produced at the position opposedto said heating element, characterized by having a valve for preventingthe liquid on the side of said liquid flow channel and the liquid on theopposite side from said liquid flow channel from mixing within a liquidsupply passage leading to either one of said first and second liquidflow channels.
 19. A liquid discharge head comprising: a grooved memberhaving integrally a plurality of discharge ports for discharging theliquid, a plurality of channels for making up a plurality of firstliquid flow channels directly communicating to and corresponding torespective discharge ports, and a recess portion for constituting afirst common liquid chamber for supplying the liquid to said pluralityof first liquid flow channels; an element substrate having a pluralityof heating elements arranged for producing a bubble in the liquid byapplying heat to the liquid; and a separation wall disposed between saidgrooved member and said element substrate, for composing a part of awall for said second liquid flow channel corresponding to said heatingelement, and having a movable member which is displaceable toward saidfirst liquid flow channel by a pressure due to a bubble produced at theposition opposed to said heating element, characterized by having avalve for preventing the liquid on the side of said liquid flow channeland the liquid on the opposite side from said liquid flow channel frommixing within a liquid supply passage leading to said first and secondliquid flow channels.
 20. A liquid discharge head according to claim 17or 19, characterized in that the valve provided on the liquid supplypassage to said first liquid flow channel and the valve provided on theliquid supply passage to said second liquid flow channel have differentcharacteristics.
 21. A liquid discharge head according to any one ofclaims 13 to 19, characterized in that said valve operates with apressure difference between liquids on both sides of said valve.
 22. Aliquid discharge head according to claim 21, characterized in that saidvalve opens only when the pressure of liquid on the side of said liquidflow channel is lower than that on the opposite side of said liquid flowchannel.
 23. A liquid discharge head according to claim 8, characterizedin that the ratio between the discharge amount of liquid into said firstliquid flow channel and that into said second liquid flow channel iscontrolled by the difference in characteristics between said checkvalves.
 24. A liquid discharge head according to claim 20, characterizedin that the ratio between the discharge amount of liquid passed intosaid first liquid flow channel and that into said second liquid flowchannel is controlled by the difference in characteristics between saidvalves.
 25. A liquid discharge head according to claim 22, characterizedby comprising a liquid tank having a positive pressure not exceeding apressure applied onto said valve from said liquid flow channel, whensaid valve begins to open.
 26. A liquid discharge head comprisingdischarge ports for discharging the liquid, a bubble producing area forproducing an air bubble in the liquid of liquid flow channels, and amovable member, disposed toward said bubble producing area, which isdisplaceable between a first position and a second position farther awayfrom said bubble producing area than said first position, the liquiddischarge head discharging the liquid in such a manner that said movablemember is displaced from said first position to said second position bya pressure due to a bubble produced in said bubble producing area, andsaid bubble is more greatly expanded downstream than upstream in adirection toward said discharge port, due to the displacement of saidmovable member, characterized by having a valve, disposed in a liquidsupply passage leading to said liquid flow channels, which can be openedor closed owing to the bubble produced by heating of the heatingelement.
 27. A liquid discharge head comprising discharge ports fordischarging the liquid, liquid flow channels each having a heatingelement for applying heat to the liquid to produce a bubble in saidliquid, and a supply passage for supplying the liquid onto said heatingelement from the upstream side of said heating element along saidheating element, and a movable member, provided toward said heatingelement, with a free end on the discharge port side, for displacing saidfree end due to a pressure caused by said bubble produced to conductsaid pressure to the discharge port side, characterized by having avalve, disposed in said liquid supply passage, which can be opened orclosed owing to the bubble produced by the heating element.
 28. A liquiddischarge head comprising discharge ports for discharging the liquid, aheating element for applying heat to the liquid to produce a bubble insaid liquid, a movable member, provided toward said heating element,with a free end on the discharge port side, for displacing said free enddue to a pressure caused by said bubble produced to conduct saidpressure to the discharge port side, and a supply passage for supplyingthe liquid onto said heating element from the upstream side thereofalong the face of said movable member closer to said heating element,characterized by having a valve disposed in said liquid supply passage,which can be opened or closed owing to the bubble produced by theheating element.
 29. A liquid discharge head comprising a first liquidflow channel communicating to a discharge port, a second liquid flowchannel having a bubble producing area for producing a bubble in saidliquid by applying heat to the liquid, and a movable member, disposedbetween said first liquid flow channel and said bubble producing area,with a free end on the discharge port side, for displacing said free endtoward said first liquid flow channel due to a pressure caused by saidbubble produced within said bubble producing area to conduct saidpressure to the discharge port side of said first liquid flow channel,characterized by having a valve, disposed in a liquid supply passageleading to each of said liquid flow channels, which can be opened orclosed owing to the bubble produced by the heating element.
 30. A liquiddischarge head comprising: a grooved member having integrally aplurality of discharge ports for discharging the liquid, a plurality ofchannels for making up a plurality of first liquid flow channelsdirectly communicating to and corresponding to respective dischargeports, and a recess portion for constituting a first common liquidchamber for supplying the liquid to said plurality of first liquid flowchannels; an element substrate having a plurality of heating elementsarranged for producing a bubble in the liquid by applying heat to theliquid; and a separation wall, disposed between said grooved member andsaid element substrate, for composing a part of a wall for said secondliquid flow channel corresponding to said heating element, and having amovable member which is displaceable toward said first liquid flowchannel by a pressure due to a bubble produced at the position opposedto said heating element, characterized by having a valve, disposed in aliquid supply passage into said liquid flow channels, which can beopened or closed owing to the bubble produced by the heating element.31. A liquid discharge head according to any one of claims 26 or 30,characterized in that said valve opens only when said bubble has beendisappeared.
 32. A liquid discharge head according to any one of claims26 to 30, characterized in that said valve opens only when liquid issupplied into said liquid flow channel.
 33. A liquid discharge headcomprising discharge ports for discharging the liquid, a bubbleproducing area for producing an air bubble in the liquid of liquid flowchannels, and a movable member, disposed toward said bubble producingarea, which is displaceable between a first position and a secondposition farther away from said bubble producing area than said firstposition, the liquid discharge head discharging the liquid in such amanner that said movable member is displaced from said first position tosaid second position by a pressure due to a bubble produced in saidbubble producing area, and said bubble is more greatly expandeddownstream than upstream in a direction toward said discharge port, dueto the displacement of said movable member, characterized by having apressure pump disposed in a liquid supply passage into said liquid flowchannels.
 34. A liquid discharge head comprising discharge ports fordischarging the liquid, liquid flow channels each having a heatingelement for applying heat to the liquid to produce a bubble in saidliquid, and a supply passage for supplying the liquid onto said heatingelement from the upstream side of said heating element along saidheating element, and a movable member, provided toward said heatingelement, with a free end on the discharge port side, for displacing saidfree end due to a pressure caused by said bubble produced to conductsaid pressure to the discharge port side, characterized by having apressure pump disposed in said liquid supply passage.
 35. A liquiddischarge head comprising discharge ports for discharging the liquid, aheating element for applying heat to the liquid to produce a bubble insaid liquid, a movable member, provided toward said heating element,with a free end on the discharge port side, for displacing said free enddue to a pressure caused by said bubble produced to conduct saidpressure to the discharge port side, and a supply passage for supplyingthe liquid onto said heating element from the upstream side thereofalong the face of said movable member closer to said heating element,characterized by having a pressure pump disposed in said liquid supplypassage.
 36. A liquid discharge head comprising a first liquid flowchannel communicating to a discharge port, a second liquid flow channelhaving a bubble producing area for producing a bubble in said liquid byapplying heat to the liquid, and a movable member, disposed between saidfirst liquid flow channel and said bubble producing area, with a freeend on the discharge port side, for displacing said free end toward saidfirst liquid flow channel due to a pressure caused by said bubbleproduced within said bubble producing area to conduct said pressure tothe discharge port side of said first liquid flow channel, characterizedby having a pressure pump disposed in a liquid supply passage into eachof said liquid flow channels.
 37. A liquid discharge head comprising: agrooved member having as a piece a plurality of discharge ports fordischarging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tosaid plurality of first liquid flow channels; an element substratehaving a plurality of heating elements arranged for producing a bubblein the liquid by applying heat to the liquid; and a separation wall,disposed between said grooved member and said element substrate, forcomposing a part of a wall for said second liquid flow channelcorresponding to said heating element, and having a movable member whichis displaceable toward said first liquid flow channel by a pressure dueto a bubble produced at the position opposed to said heating element,characterized by having a pressure pump disposed in a liquid supplypassage into said liquid flow channels.
 38. A liquid discharge headcomprising discharge ports for discharging the liquid, a bubbleproducing area for producing an air bubble in the liquid of liquid flowchannels, and a movable member, disposed toward said bubble producingarea, which is displaceable between a first position and a secondposition farther away from said bubble producing area than said firstposition, the liquid discharge head discharging the liquid in such amanner that said movable member is displaced from said first position tosaid second position by a pressure due to a bubble produced in saidbubble producing area, and said bubble is more greatly expandeddownstream than upstream in a direction toward said discharge port, dueto the displacement of said movable member, characterized in that therecovery operation for said discharge ports is performed by dischargingthe liquid from said discharge ports owing to pressure.
 39. A liquiddischarge head comprising discharge ports for discharging the liquid,liquid flow channels each having a heating element for applying heat tothe liquid to produce a bubble in said liquid, and a supply passage forsupplying the liquid onto said heating element from the upstream side ofsaid heating element along said heating element, and a movable member,provided toward said heating element, with a free end on the dischargeport side, for displacing said free end due to a pressure caused by saidbubble produced to conduct said pressure to the discharge port side,characterized in that the recovery operation for said discharge ports isperformed by discharging the liquid from said discharge ports owing topressure.
 40. A liquid discharge head comprising discharge ports fordischarging the liquid, a heating element for applying heat to theliquid to produce a bubble in said liquid, a movable member, providedtoward said heating element, with a free end on the discharge port side,for displacing said free end due to a pressure caused by said bubbleproduced to conduct said pressure to the discharge port side, and asupply passage for supplying the liquid onto said heating element fromthe upstream side thereof along the face of said movable member closerto said heating element, characterized in that the recovery operationfor said discharge ports is performed by discharging the liquid fromsaid discharge ports owing to pressure.
 41. A liquid discharge headcomprising a first liquid flow channel communicating to a dischargeport, a second liquid flow channel having a bubble producing area forproducing a bubble in said liquid by applying heat to the liquid, and amovable member, disposed between said first liquid flow channel and saidbubble producing area, with a free end on the discharge port side, fordisplacing said free end toward said first liquid flow channel due to apressure caused by said bubble produced within said bubble producingarea to conduct said pressure to the discharge port side of said firstliquid flow channel, characterized in that the recovery operation forsaid discharge ports is performed by discharging the liquid from saiddischarge ports owing to pressure.
 42. A liquid discharge headcomprising: a grooved member having integrally a plurality of dischargeports for discharging the liquid, a plurality of channels for making upa plurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tosaid plurality of first liquid flow channels; an element substratehaving a plurality of heating elements arranged for producing a bubblein the liquid by applying heat to the liquid; and a separation wall,disposed between said grooved member and said element substrate, forcomposing a part of a wall for said second liquid flow channelcorresponding to said heating element, and having a movable member whichis displaceable toward said first liquid flow channel by a pressure dueto a bubble produced at the position opposed to said heating element,characterized in that the recovery operation for said discharge ports isperformed by discharging the liquid from said discharge ports owing topressure.
 43. A liquid discharge head according to any one of claims 33to 37, characterized in that after said recovery operation, the printingoperation is performed by discharging the liquid from said dischargeports.
 44. A liquid discharge head according to any one of claims 38 to42, characterized in that after said recovery operation, the printingoperation is performed by discharging the liquid from said dischargeports.
 45. A liquid discharge head comprising discharge ports fordischarging the liquid, a bubble producing area for producing an airbubble in the liquid of liquid flow channels, and a movable member,disposed toward said bubble producing area, which is displaceablebetween a first position and a second position farther away from saidbubble producing area than said first position, the liquid dischargehead discharging the liquid in such a manner that said movable member isdisplaced from said first position to said second position by a pressuredue to a bubble produced in said bubble producing area, and said bubbleis more greatly expanded downstream than upstream in a direction towardsaid discharge port, due to the displacement of said movable member,characterized by having a cap attached to said liquid discharge headwhich allows the opening or closing of said discharge ports freely. 46.A liquid discharge head comprising discharge ports for discharging theliquid, liquid flow channels each having a heating element for applyingheat to the liquid to produce a bubble in said liquid, and a supplypassage for supplying the liquid onto said heating element from theupstream side of said heating element along said heating element, and amovable member, provided toward said heating element, with a free end onthe discharge port side, for displacing said free end due to a pressurecaused by said bubble produced to conduct said pressure to the dischargeport side, characterized by having a cap attached to said liquiddischarge head which allows the opening or closing of said dischargeports freely.
 47. A liquid discharge head comprising discharge ports fordischarging the liquid, a heating element for applying heat to theliquid to produce a bubble in said liquid, a movable member, providedtoward said heating element, with a free end on the discharge port side,for displacing said free end due to a pressure caused by said bubbleproduced to conduct said pressure to the discharge port side, and asupply passage for supplying the liquid onto said heating element fromthe upstream side thereof along the face of said movable member closerto said heating element, characterized by having a cap attached to saidliquid discharge head which allows the opening or closing of saiddischarge ports freely.
 48. A liquid discharge head comprising: a firstliquid flow channel communicating to a discharge port, a second liquidflow channel having a bubble producing area for producing a bubble insaid liquid by applying heat to the liquid, and a movable member,disposed between said first liquid flow channel and said bubbleproducing area, with a free end on the discharge port side, fordisplacing said free end toward said first liquid flow channel due to apressure caused by said bubble produced within said bubble producingarea to conduct said pressure to the discharge port side of said firstliquid flow channel, characterized by further comprising, a cap attachedto said liquid discharge head which allows the opening or closing ofsaid discharge ports freely.
 49. A liquid discharge head comprising: agrooved member having integrally a plurality of discharge ports fordischarging the liquid, a plurality of channels for making up aplurality of first liquid flow channels directly communicating to andcorresponding to respective discharge ports, and a recess portion forconstituting a first common liquid chamber for supplying the liquid tosaid plurality of first liquid flow channels, an element substratehaving a plurality of heating elements arranged for producing a bubblein the liquid by applying heat to the liquid, and a separation wall,disposed between said grooved member and said element substrate, forcomposing a part of a wall for said second liquid flow channelcorresponding to said heating element, and having a movable member whichis displaceable toward said first liquid flow channel by a pressure dueto a bubble produced at the position opposed to said heating element,characterized by further comprising, a cap attached to said liquiddischarge head which allows the opening or closing of said dischargeports freely.
 50. A liquid discharge head according to any one of claims45 to 49, characterized in that said cap can open or close saiddischarge ports by sliding with respect to said discharge ports.
 51. Aliquid discharge head according to any one of claims 45 to 49,characterized in that said cap can open or close said discharge ports byrevolving with respect to said discharge ports.
 52. A liquid dischargehead according to any one of claims 45 to 49, characterized in that saidcap can open said discharge ports by separating away from said dischargeports, and close said discharge ports by making close contact with saiddischarge ports.
 53. A liquid discharge head according to any one ofclaims 45 to 49, characterized in that said cap comprises a liquidholding member.
 54. A liquid discharge head according to any one ofclaims 45 to 49, characterized in that said cap operates by movement ofa carriage when said liquid discharge head is mounted on said carriage.55. A liquid discharge head according to any one of claims 45 to 49,characterized in that said cap holds the liquid discharged from saiddischarge ports in the recovery operation for said discharge ports. 56.A liquid discharge head comprising: discharge ports from which thedischarge liquid is discharged, first liquid flow channels forconducting the discharge liquid to said discharge ports, heatingelements for generating heat to produce a bubble in the bubbling liquid,second liquid flow channels for conducting the bubbling liquid to saidheating elements, and a separation wall having a movable member disposedalong said heating element for separation between said first liquid flowchannel and said second liquid flow channel, wherein the liquiddischarge head discharges the discharge liquid from said discharge portsowing to a bubble produced, characterized in that said bubbling liquidcontains the liquid which has been treated for bubble generationstabilization.
 57. A liquid discharge head according to claim 56,characterized in that said separation wall is made of metal, and saidbubbling liquid is predeaerated.
 58. A liquid discharge head accordingto claim 57, characterized by further comprising deaerating means fordeaerating said bubbling liquid.
 59. A liquid discharge head accordingto claim 58, characterized in that said deaerating means comprises: apump for sucking the gas from said bubbling liquid, a gas permeablemembrane for permeating only the gas from said bubbling liquid, a gasexhauster for exhausting the gas which has passed through said gaspermeable membrane, and a deaerated liquid supply port for supplyingsaid bubbling liquid which has been deaerated into said second liquidflow channels.
 60. A liquid discharge head according to claim 56,characterized in that said bubbling liquid is added with a burntdeposits antisticking agent.
 61. A liquid discharge head according toclaim 60, characterized in that said burnt deposits antisticking agentis a material having the effect of exfoliating the burnt deposits whichhave deposited on said heating element.
 62. A liquid discharge headaccording to claim 61, characterized in that said burnt depositsantisticking agent is a material for enhancing the wettability andhaving the effect of preventing the burnt deposits from sticking ontosaid heating element.
 63. A liquid discharge head according to claim 61or 62, characterized in that said burnt deposits antisticking agent is asurfactant.
 64. A liquid discharge head according to claim 56,characterized in that said discharge liquid and said bubbling liquid arethe same liquid.
 65. A liquid discharge head according to claim 56,characterized in that said discharge liquid and said bubbling liquid aredifferent liquids from each other.
 66. A liquid discharge headcomprising; discharge ports from which the discharge liquid isdischarged, first liquid flow channels for conducting the dischargeliquid to said discharge ports, heating elements for generating heat toproduce a bubble in the bubbling liquid, second liquid flow channels forconducting the bubbling liquid to said heating elements, and aseparation wall having a movable member disposed toward said heatingelement for separation between said first liquid flow channel and saidsecond liquid flow channel, wherein the liquid discharge head dischargesthe discharge liquid from said discharge ports in such a manner thatsaid movable member is displaced from said first position to said secondposition by a pressure due to a bubble produced on said heating element,thereby more greatly expanding said bubble downstream than upstream in adirection toward said discharge ports, characterized in that saidbubbling liquid contains the liquid which has been treated for bubblegeneration stabilization.
 67. A liquid discharge head according to claim66, characterized in that said separation wall is made of metal, andsaid bubbling liquid is predeaerated.
 68. A liquid discharge headaccording to claim 67, characterized by further comprising deaerationmeans for deaerating said bubbling liquid.
 69. A liquid discharge headaccording to claim 68, characterized in that said deaerating meanscomprises: a pump for sucking the gas from said bubbling liquid, a gaspermeable membrane for permeating only the gas from said bubblingliquid, a gas exhauster for exhausting the gas which has passed throughsaid gas permeable membrane, and a deaerated liquid supply port forsupplying said bubbling liquid which has been deaerating into saidsecond liquid flow channels.
 70. A liquid discharge head according toclaim 66, characterized in that said bubbling liquid is added with aburnt deposits antisticking agent.
 71. A liquid discharge head accordingto claim 70, characterized in that said burnt deposits antistickingagent is a material having the effect of exfoliating the burnt depositswhich have deposited on said heating element.
 72. A liquid dischargehead according to claim 71, characterized in that said burnt depositsantisticking agent is a material for enhancing the wettability andhaving the effect of preventing the burnt deposits from sticking ontosaid heating element.
 73. A liquid discharge head according to claim 71or 72, characterized in that said burnt deposits antisticking agent is asurfactant.
 74. A liquid discharge head according to claim 66,characterized in that said discharge liquid and said bubbling liquid arethe same liquid.
 75. A liquid discharge head according to claim 66,characterized in that said discharge liquid and said bubbling liquid aredifferent liquids from each other.
 76. A liquid discharge head accordingto claim 56 or 66, characterized in that said gas permeable membrane ismade of ethylene fluoride.
 77. A liquid discharge head according to anyone of claims 1 to 7, characterized by further comprising a valvedisposed in a liquid supply passage into said liquid flow channel, whichcan be opened or closed owing to a bubble produced by the heatingelement.
 78. A liquid discharge head according to any one of claims 1 to7, characterized by further comprising a pressure pump disposed in aliquid supply passage into said liquid flow channel.
 79. A liquiddischarge head according to any one of claims 1 to 7, characterized byfurther comprising a cap attached on said liquid discharge head, whichallows the opening and closing of said discharge ports freely.
 80. Aliquid discharge head according to any one of claims 33 to 37,characterized by further comprising a cap attached on said liquiddischarge head, which allows the opening and closing of said dischargeports freely.
 81. A liquid discharge head according to any one of claims1 to 7, characterized by further comprising a valve disposed in a liquidsupply passage into said liquid flow channel, which can be opened orclosed owing to a bubble produced by the heating element, a pressurepump disposed in a liquid supply passage into said liquid flow channel,and a cap attached on said liquid discharge head, which allows theopening and closing of said discharge ports freely.
 82. A liquiddischarge head according to any one of claims 4 to 7, characterized byfurther comprising a valve disposed in a liquid supply passage into saidliquid flow channel, which can be opened or closed owing to a bubbleproduced by the heating element, a pressure pump disposed in a liquidsupply passage into said liquid flow channel, a cap attached on saidliquid discharge head, which allows the opening and closing of saiddischarge ports freely, and deaeration means for deaerating the liquidwithin said second liquid flow channel.
 83. A head cartridge comprisinga liquid discharge head according to any one of claims 1 to 7, and aliquid vessel for holding the liquid to be supplied to said liquiddischarge head.
 84. A head cartridge according to claim 82,characterized in that said liquid discharge head and said liquid vesselare separable.
 85. A head cartridge according to claim 82, characterizedin that said liquid vessel is refilled with the liquid.
 86. A headcartridge according to claim 82, characterized in that said liquidvessel is provided with a liquid inlet opening for refilling the liquid.87. A head cartridge comprising a liquid discharge head according to anyone of claims 1 to 7, and liquid vessels for holding the dischargeliquid to be supplied into said first liquid flow channel and saidbubbling liquid to be supplied into said second liquid flow channel. 88.A head cartridge according to claim 87, characterized in that the liquidvessel for holding said bubbling liquid is one for deaerating andbubbling liquid.
 89. A liquid discharge apparatus for performing therecording with a liquid discharge head mounted on a carriage, the liquiddischarge head comprising: a first liquid flow channel communicating toa discharge port, a second liquid flow channel containing a bubbleproducing area and disposed adjacent said first liquid flow channel, anda movable member, disposed toward said bubble producing area, which isdisplaceable between a first position and a second position farther awayfrom said bubble producing area than said first position, wherein saidliquid discharge head discharges the liquid from discharge ports in sucha manner that said movable member is displaced from said first positionto said second position due to a pressure caused by said bubble producedwithin said bubble producing area to conduct said pressure in adirection toward the discharge ports, characterized by furthercomprising, recovery means for supplying the liquid to said first andsecond liquid flow channels, independently, and exhausting the liquidfrom said discharge ports, and liquid reverse flow preventing means forpreventing any reverse flow of liquid from occurring in said first andsecond liquid flow channels.
 90. A liquid discharge apparatus accordingto claim 89, characterized in that said liquid discharge head isprovided with a supply system for receiving the supply from a firstliquid vessel for containing the first liquid and a second liquid vesselfor containing the second liquid, said recovery means is provided withliquid transport means for transporting the liquid to said first andsecond liquid flow channels, independently, and said liquid transportmeans transports the first liquid contained within said first liquidvessel to said first liquid flow channel, and the second liquidcontained within said second liquid vessel to said second liquid flowchannel, independently.
 91. A liquid discharge apparatus according toclaim 90, characterized in that said liquid transport means is a pumpfor sucking the liquid from said first and second liquid vessels, andforcefully feeding the liquid to said first and second liquid flowchannels.
 92. A liquid discharge apparatus according to claim 90,characterized in that said first and second liquid vessels and saidliquid discharge head are connected via a tube, and said pump is a tubepump using said tube.
 93. A liquid discharge apparatus according toclaim 90, characterized in that said liquid transport means is a pumpfor pressurizing said first and second liquid vessels and forcefullyfeeding the liquid to said first and second liquid flow channels.
 94. Aliquid discharge apparatus according to claim 93, characterized in thatsaid pump is a tube pump for feeding the air into said first and secondliquid vessels.
 95. A liquid discharge apparatus according to claim 93or 94, characterized in that said liquid discharge head and said firstand second liquid vessels are integrally constituted.
 96. A liquiddischarge apparatus according to claim 92 or 94, characterized in thatthe deformation of tube due to a roller of said tube pump is differentbetween said first liquid flow channel side and said second liquid flowchannel.
 97. A liquid discharge apparatus according to claim 92 or 94,characterized in that said tube pump is also used as said liquid reverseflow preventing means.
 98. A liquid discharge apparatus according toclaim 90, characterized in that said liquid discharge head, said liquidvessel for supplying the liquid to said liquid discharge head, and saidliquid transport means are mounted on a carriage.
 99. A liquid dischargeapparatus according to claim 90, characterized in that said liquiddischarge head and said liquid vessel for supplying the liquid to saidliquid discharge head are mounted on the carriage, and said liquidtransport means is secured to the device main body.
 100. A liquiddischarge apparatus according to claim 98 or 99, characterized in thatsaid liquid transport means is a pump for sucking the liquid from saidliquid vessels, and forcefully feeding the liquid to said liquiddischarge head.
 101. A liquid discharge apparatus according to claim 98or 99, characterized in that said liquid transport means is a pump forpressurizing said liquid vessels and forcefully feeding the liquid tosaid liquid discharge head.
 102. A liquid discharge apparatus accordingto claim 101, characterized in that said liquid discharge head and saidliquid vessels are integrally constituted.
 103. A liquid dischargeapparatus according to any one of claims 1 to 7, characterized byfurther comprising drive signal supply means for supplying a drivesignal for discharging the liquid from said liquid discharge head. 104.A liquid discharge apparatus according to any one of claims 1 to 7,characterized by further comprising recording medium conveying means forconveying the recording medium for accepting the liquid discharged fromsaid liquid discharge head.
 105. A liquid discharge apparatus accordingto claim 103 or 104, characterized in that the recording is performed insuch a manner as to discharge the ink from said liquid discharge headand attach the ink onto the recording sheet.
 106. A liquid dischargeapparatus according to claim 103 or 104, characterized in that therecording is performed in such a manner as to discharge the ink fromsaid liquid discharge head and attach the ink onto the cloths.
 107. Aliquid discharge apparatus according to claim 103 or 104, characterizedin that the recording is performed in such a manner as to discharge theink from said liquid discharge head and attach the ink onto theplastics.
 108. A liquid discharge apparatus according to claim 103 or104, characterized in that the recording is performed in such a manneras to discharge the ink from said liquid discharge head and attach theink onto the metal.
 109. A liquid discharge apparatus according to claim103 or 104, characterized in that the recording is performed in such amanner as to discharge the ink from said liquid discharge head andattach the ink onto the wood.
 110. A liquid discharge apparatusaccording to claim 103 or 104, characterized in that the recording isperformed in such a manner as to discharge the ink from said liquiddischarge head and attach the ink onto the leather.
 111. A liquiddischarge apparatus according to claim 103 or 104, characterized in thatthe color recording is performed in such a manner as to discharge aplurality of color recording liquids from said liquid discharge headsand attach the plurality of color recording liquids onto the recordingmedium.
 112. A liquid discharge apparatus according to claim 103 or 104,characterized in that said discharge ports are arranged over an entirewidth of the recordable area for the recording medium.
 113. A liquiddischarge apparatus having a liquid discharge head comprising dischargeports for discharging the liquid, a bubble producing area for producingan air bubble in the liquid of liquid flow channels, and a movablemember, disposed toward said bubble producing area, which isdisplaceable between a first position and a second position farther awayfrom said bubble producing area than said first position, the liquiddischarge head discharging the liquid in such a manner that said movablemember is displaced from said first position to said second position bya pressure due to a bubble produced in said bubble producing area toconduct said bubble in a discharge direction owing to displacement ofsaid movable member, wherein the liquid discharge apparatus is provided,in a liquid supply passage into said liquid discharge head, with atleast one of a reverse flow preventing valve for allowing only theliquid to be flowed in a head direction, a deaerator for removing thegas dissolved in the liquid, a liquid pump for transporting the liquidin the head direction, an active valve which is capable of controllingthe opening and closing of valve, and a cap for accepting the liquidfrom the discharge ports of said liquid discharge head and openably orclosably attached over the discharge ports of said head upon theoperation of the carriage which mounts the head thereon, characterizedin that the reliability of liquid discharge is enhanced with the aboveconstitution.
 114. A liquid discharge apparatus having a liquiddischarge head comprising a first liquid channel communicating todischarge ports, a second liquid flow channel having a bubble producingarea for producing an air bubble in the liquid by applying heat to theliquid, and a movable member, disposed between said first liquid flowchannel and said bubble producing area, with a free end on the dischargeport side, for displacing said free end to the first liquid flow channeldue to a pressure caused by a bubble produced within said bubbleproducing area, to conduct said pressure to the discharge port side ofsaid first liquid flow channel, wherein the liquid discharge apparatusis provided, in each liquid supply passage into said liquid dischargehead, with at least one of a reverse flow preventing valve for allowingonly the liquid to be flowed in a head direction, a deaerator forremoving the gas dissolved in the liquid, a liquid pump for transportingthe liquid in the head direction, an active valve which is capable ofcontrolling the opening and closing of valve, and a cap for acceptingthe liquid from the discharge ports of said liquid discharge head andopenably or closably attached over the discharge ports of said head uponthe operation of the carriage which mounts the head thereon,characterized in that the reliability of liquid discharge is enhancedwith the above constitution.